build: pin rust version to 1.46.0

[sinato]

This PR pins the version of the rust toolchain to be used in the build and CI of this project ( closes #247 ) .

• Add rust-toolchain file to pin the version used for rustup
  • ref: https://github.com/rust-lang/rustup/blob/bde7f787d7/doc/src/overrides.md#the-toolchain-file
• Modify CI / release workflow to read rust-toolchain file (just remove the toolchain input)
  • ref: https://github.com/actions-rs/toolchain/tree/69f9ca11d94b20d95d67be4902f28e68f089145c#the-toolchain-file

[codecov]

Codecov Report

Merging #269 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #269   +/-   ##
=======================================
  Coverage   79.05%   79.05%           
=======================================
  Files         214      214           
  Lines       12808    12808           
=======================================
  Hits        10125    10125           
  Misses       2683     2683           

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[baszalmstra]

With these changes, I think you can also remove the nightly and beta CI stages. They dont make sense to me if you pin the Rust version anyway. WDYT? what does vector do?

[sinato]

With these changes, I think you can also remove the nightly and beta CI stages. They dont make sense to me if you pin the Rust version anyway. WDYT? what does vector do?

As far as I understand, vector only use the pinned version and stable. I also think beta and nightly are no longer needed.
Fixed: a1fedce

[Wodann]

Just checking, but did you want to squash some of the commits or can I merge it as is? Either is fine by me 🙂

[sinato]

Thank you for the review! Can you merge them as is? I think each commit meaningful enough.