ci: cache wasm32-unknown-unknown build target in CI pipeline

[Icahbod]

Both .github/workflows/ci.yml and .github/workflows/release-hash.yml cross-compile to wasm32-unknown-unknown, but the Swatinem/rust-cache configuration does not explicitly include the WASM target build artefacts or the soroban-sdk crate under that target. Every CI run re-builds the standard library for WASM from scratch, lengthening PR validation by minutes. Add a target-specific cache key that captures target/wasm32-unknown-unknown and the Cargo registry state for the WASM triple so subsequent runs benefit from the cache. Verify by running the workflow on a clean runner and on a warmed runner and reporting the wall-clock delta.

[Tobi-8]

Please maintainer
Assign me to this issue
I can confidently solve it with my experience

[Unclebaffa]

Hi team,

I would love to take ownership of this issue. Being actively engaged with the GrantFox repository and bringing over two years of professional development experience, I can quickly optimize this CI pipeline to drastically reduce PR validation times.

Here is my straightforward implementation plan:

1. Cache Configuration Update

• Modify both .github/workflows/ci.yml and .github/workflows/release-hash.yml.
• Update the Swatinem/rust-cache configuration to explicitly include target/wasm32-unknown-unknown and the specific Cargo registry state for the WASM triple via a custom, target-specific cache key.

2. Workflow Validation & Benchmarking

• Run the updated workflows on a clean runner to establish the baseline compilation time.
• Execute a subsequent run to verify the cache hit.
• Document the wall-clock delta between the clean and warmed runners directly in the PR description to prove the optimization.

Let me know if this plan looks good. If so, please assign me and I will get the PR and benchmarks up shortly!

[grantfox-oss]

🦊 GrantFox — @Unclebaffa has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #46)
2. Your PR will be reviewed by the ApexChainx maintainers

Good luck! Track your progress on GrantFox.

[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox as part of the Official Campaign campaign!

@Unclebaffa's PR #49 was approved and merged by @Icahbod.

🏆 @Unclebaffa: You earned 40 FoxPoints for this contribution! Your current tier: Builder (1,231 total points). Track your full progress on GrantFox.

👏 Great work, @Unclebaffa! Keep contributing to ApexChainx.