ci: pin version of the llvm builder

[antonbaliasnikov]

What ❔

Pin the version of the LLVM builder tool instead of using latest from cargo crates.

Why ❔

Although it can be nice to always use the most recent builder, it is risky, because regardless of how well it is tested in the builder repository, there could be unexpected problems in CI caused by an update in the other repository.

It is also impossible right now to change the builder name if the version is not pinned. This PR makes this possible and puts the builder update process under control.

Checklist

• PR title corresponds to the body of PR (we generate changelog entries from PRs).
• Tests for the changes have been added / updated.
• Documentation comments have been added / updated.
• Code has been formatted via cargo fmt and checked with cargo clippy.

[github-actions]

Benchmark results:

╔═╡ Size (-%) ╞════════════════╡ All M3B3 ╞═╗
║ Mean                                0.000 ║
║ Best                                0.000 ║
║ Worst                               0.000 ║
║ Total                               0.000 ║
╠═╡ Cycles (-%) ╞══════════════╡ All M3B3 ╞═╣
║ Mean                                0.000 ║
║ Best                                0.000 ║
║ Worst                               0.000 ║
║ Total                               0.000 ║
╠═╡ Ergs (-%) ╞════════════════╡ All M3B3 ╞═╣
║ Mean                                0.000 ║
║ Best                                0.000 ║
║ Worst                               0.000 ║
║ Total                               0.000 ║
╚═══════════════════════════════════════════╝

╔═╡ Size (-%) ╞════════════════╡ All MzB3 ╞═╗
║ Mean                                0.000 ║
║ Best                                0.000 ║
║ Worst                               0.000 ║
║ Total                               0.000 ║
╠═╡ Cycles (-%) ╞══════════════╡ All MzB3 ╞═╣
║ Mean                                0.000 ║
║ Best                                0.000 ║
║ Worst                               0.000 ║
║ Total                               0.000 ║
╠═╡ Ergs (-%) ╞════════════════╡ All MzB3 ╞═╣
║ Mean                                0.000 ║
║ Best                                0.000 ║
║ Worst                               0.000 ║
║ Total                               0.000 ║
╚═══════════════════════════════════════════╝

╔═╡ Size (-%) ╞════════╡ Precompiles M3B3 ╞═╗
║ Mean                                0.000 ║
║ Best                                0.000 ║
║ Worst                               0.000 ║
║ Total                               0.000 ║
╠═╡ Cycles (-%) ╞══════╡ Precompiles M3B3 ╞═╣
║ Mean                                0.000 ║
║ Best                                0.000 ║
║ Worst                               0.000 ║
║ Total                               0.000 ║
╠═╡ Ergs (-%) ╞════════╡ Precompiles M3B3 ╞═╣
║ Mean                                0.000 ║
║ Best                                0.000 ║
║ Worst                               0.000 ║
║ Total                               0.000 ║
╚═══════════════════════════════════════════╝

╔═╡ Size (-%) ╞════════╡ Precompiles MzB3 ╞═╗
║ Mean                                0.000 ║
║ Best                                0.000 ║
║ Worst                               0.000 ║
║ Total                               0.000 ║
╠═╡ Cycles (-%) ╞══════╡ Precompiles MzB3 ╞═╣
║ Mean                                0.000 ║
║ Best                                0.000 ║
║ Worst                               0.000 ║
║ Total                               0.000 ║
╠═╡ Ergs (-%) ╞════════╡ Precompiles MzB3 ╞═╣
║ Mean                                0.000 ║
║ Best                                0.000 ║
║ Worst                               0.000 ║
║ Total                               0.000 ║
╚═══════════════════════════════════════════╝

╔═╡ Size (-%) ╞══════════╡ Real life M3B3 ╞═╗
║ Mean                                0.000 ║
║ Best                                0.000 ║
║ Worst                               0.000 ║
║ Total                               0.000 ║
╠═╡ Cycles (-%) ╞════════╡ Real life M3B3 ╞═╣
║ Mean                                0.000 ║
║ Best                                0.000 ║
║ Worst                               0.000 ║
║ Total                               0.000 ║
╠═╡ Ergs (-%) ╞══════════╡ Real life M3B3 ╞═╣
║ Mean                                0.000 ║
║ Best                                0.000 ║
║ Worst                               0.000 ║
║ Total                               0.000 ║
╚═══════════════════════════════════════════╝

╔═╡ Size (-%) ╞══════════╡ Real life MzB3 ╞═╗
║ Mean                                0.000 ║
║ Best                                0.000 ║
║ Worst                               0.000 ║
║ Total                               0.000 ║
╠═╡ Cycles (-%) ╞════════╡ Real life MzB3 ╞═╣
║ Mean                                0.000 ║
║ Best                                0.000 ║
║ Worst                               0.000 ║
║ Total                               0.000 ║
╠═╡ Ergs (-%) ╞══════════╡ Real life MzB3 ╞═╣
║ Mean                                0.000 ║
║ Best                                0.000 ║
║ Worst                               0.000 ║
║ Total                               0.000 ║
╚═══════════════════════════════════════════╝