Make sure we're using indexes during rollbacks 13.6.0.5

[kderme]

Fixes #2083 (comment) for 13.6.0.5.

The queryMinRefId query uses

SELECT id FROM <table> WHERE <field> >= $1 ORDER BY id ASC LIMIT 1.

The planner sometimes picks a bad plan:

Index Scan using tx_pkey on tx
Filter: (block_id >= $1)

the filter is not Index Cond, so this ends up in a sequential scan.
The index refers to the primary key and is only used for sorting.
Instead we use a simpler query without ORDER BY:

SELECT id FROM <table> WHERE <field> >= $1 LIMIT 10000

This forces the planner to use the field's index.
The results are fetched and the minimum is found in Haskell.
Near the tip this returns only a handful of rows.

If there are more than 10000 matching rows (large rollback),
we fall back to the original ORDER BY id ASC LIMIT 1 query.

[angerman]

I think this is good to merge.

• The Haskell CI / build failures are an issue with the devx closures that are missing git.
• The profiled builds failing isn't a big deal I believe.
• The Check HLint / build failure is due to some dependency setup. It's just HLint, so it's at best formatting issues we didn't catch.
• Looking at the relevant hydra build, everything seems to be green (except for profiling). Thus something with the notification delivery seems broken with the hydra -> github status reports.