ci: remove GNU build caching from GnuTests workflow

[ChrisDryden]

I unfortunately created a mess by trying to fix the issue of the Makefile being regenerated when the tests were being run where now when CI pulls the GNU build from the cache it will rebuild the entire project before running the GNU tests which swaps the binary thats being compared to the GNU binaries.

I think this is still the right way to fix forward because if you look at the timing: : https://github.com/uutils/coreutils/actions/runs/22039759086/job/63678632753 this one with no cache and https://github.com/uutils/coreutils/actions/runs/22039759086/job/63678632753 this one with the cache its still faster to not use the cache because the rebuilding of the Makefile takes more time than the cache saves.

[ChrisDryden]

@sylvestre this one is a bit urgent, right now if the cache is hit it will not give accurate results for the GNU tests. Either reverting this PR #10907 or merging this one would fix it

[oech3]

You are a collaborator, so you can merge this by yourself if urgent

[oech3]

I guess we caches too few files instead of all of GNU files.

[github-actions]

GNU testsuite comparison:

GNU test failed: tests/cksum/cksum-a. tests/cksum/cksum-a is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/cksum/cksum-c. tests/cksum/cksum-c is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/date/date-debug. tests/date/date-debug is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/date/date-locale-hour. tests/date/date-locale-hour is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/dd/conv-case. tests/dd/conv-case is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/env/env-signal-handler. tests/env/env-signal-handler is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/fmt/width. tests/fmt/width is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/ls/stat-free-symlinks. tests/ls/stat-free-symlinks is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/misc/close-stdout. tests/misc/close-stdout is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/misc/getopt_vs_usage. tests/misc/getopt_vs_usage is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/misc/kill. tests/misc/kill is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/misc/read-errors. tests/misc/read-errors is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/misc/write-errors. tests/misc/write-errors is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/mv/meta-to-xpart. tests/mv/meta-to-xpart is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/mv/mv-special-2. tests/mv/mv-special-2 is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/nproc/nproc-quota-systemd. tests/nproc/nproc-quota-systemd is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/pr/pr-tests. tests/pr/pr-tests is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/rm/one-file-system. tests/rm/one-file-system is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/sort/sort-month. tests/sort/sort-month is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/split/split-io-err. tests/split/split-io-err is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/tac/tac. tests/tac/tac is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/tac/tac-locale. tests/tac/tac-locale is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/tail/debug. tests/tail/debug is passing on 'main'. Maybe you have to rebase?
GNU test failed: tests/tail/inotify-rotate-resources. tests/tail/inotify-rotate-resources is passing on 'main'. Maybe you have to rebase?
Skip an intermittent issue tests/misc/stdbuf (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/pr/bounded-memory (fails in this run but passes in the 'main' branch)
Skip an intermittent issue tests/tail/follow-name (fails in this run but passes in the 'main' branch)
Skipping an intermittent issue tests/misc/usage_vs_getopt (passes in this run but fails in the 'main' branch)
Congrats! The gnu test tests/basenc/base64 is no longer failing!
Congrats! The gnu test tests/basenc/basenc is no longer failing!
Congrats! The gnu test tests/cksum/cksum-base64 is no longer failing!
Congrats! The gnu test tests/cksum/md5sum is no longer failing!
Congrats! The gnu test tests/cp/fail-perm is no longer failing!
Congrats! The gnu test tests/cut/cut is no longer failing!
Congrats! The gnu test tests/df/df-output is no longer failing!
Congrats! The gnu test tests/du/files0-from is no longer failing!
Congrats! The gnu test tests/du/threshold is no longer failing!
Congrats! The gnu test tests/env/env-S is no longer failing!
Congrats! The gnu test tests/factor/factor is no longer failing!
Congrats! The gnu test tests/install/basic-1 is no longer failing!
Congrats! The gnu test tests/ls/color-norm is no longer failing!
Congrats! The gnu test tests/ls/time-style-diag is no longer failing!
Congrats! The gnu test tests/misc/comm is no longer failing!
Congrats! The gnu test tests/misc/xstrtol is no longer failing!
Congrats! The gnu test tests/mv/diag is no longer failing!
Congrats! The gnu test tests/mv/dir2dir is no longer failing!
Congrats! The gnu test tests/mv/dup-source is no longer failing!
Congrats! The gnu test tests/mv/trailing-slash is no longer failing!
Congrats! The gnu test tests/rm/inaccessible is no longer failing!
Congrats! The gnu test tests/rm/v-slash is no longer failing!
Congrats! The gnu test tests/sort/sort-merge is no longer failing!
Congrats! The gnu test tests/stat/stat-printf is no longer failing!
Congrats! The gnu test tests/uniq/uniq is no longer failing!
Note: The gnu test tests/dd/fail-ftruncate-fstat is now being skipped but was previously passing.
Note: The gnu test tests/rm/rm-readdir-fail is now being skipped but was previously passing.
Note: The gnu test tests/sort/sort-locale is now being skipped but was previously passing.
Note: The gnu test tests/unexpand/bounded-memory is now being skipped but was previously passing.
Congrats! The gnu test tests/ls/no-cap is now passing!
Congrats! The gnu test tests/tail/tail-n0f is now passing!

[ChrisDryden]

That comment matches all of the GNU tests that we were expecting to fail, seems like it fixed it