fix(ci): rust cache needs to be cuda architecture specific

[jonathanpwang]

CUDA workflows use rust cache but stark-backend's rust cache contains cuda architecture specific machine code.
We make a composite github action that wraps Swatinem/rust-cache and adds the cuda arch as a cache key.

[Copilot]

Pull request overview

This PR fixes a critical caching issue in CUDA workflows where Rust caches containing architecture-specific CUDA machine code were being incorrectly shared across systems with different GPU compute capabilities. The solution introduces a composite GitHub Action that wraps Swatinem/rust-cache@v2 and automatically appends the GPU architecture to the cache key, ensuring proper cache isolation.

Key changes:

• Created a new composite action .github/actions/rust-cache-cuda that detects GPU compute capability and includes it in the cache key
• Updated all CUDA-enabled workflows to use the new composite action instead of directly using Swatinem/rust-cache@v2
• Ensured the action handles both GPU and non-GPU environments by setting appropriate cache key suffixes

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
.github/actions/rust-cache-cuda/action.yml	New composite action that wraps rust-cache with GPU architecture detection to create CUDA-specific cache keys
.github/workflows/lints.yml	Updated CUDA lint job to use the new rust-cache-cuda composite action
.github/workflows/guest-lib-tests.cuda.yml	Updated guest library CUDA tests to use architecture-specific caching
.github/workflows/extension-tests.cuda.yml	Updated extension CUDA tests to use architecture-specific caching
.github/workflows/benchmark-call.yml	Updated benchmark workflow to use rust-cache-cuda (handles both GPU and non-GPU runs)
.github/workflows/base-tests.cuda.yml	Updated base CUDA tests to use architecture-specific caching

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[github-actions]

group	app.proof_time_ms	app.cycles	app.cells_used	leaf.proof_time_ms	leaf.cycles	leaf.cells_used
verify_fibair	232	322,610	2,058,654	-	-	-
fibonacci	(+27 [+2.8%]) 994	1,500,209	2,100,402	-	-	-
regex	(+26 [+1.1%]) 2,375	4,137,502	17,695,216	-	-	-
ecrecover	(+41 [+5.7%]) 766	122,859	2,263,998	-	-	-
pairing	(+32 [+2.3%]) 1,450	1,745,742	25,468,210	-	-	-

Commit: 70b99ef

Benchmark Workflow