Add dependency caching, test runs, and precise path triggers in workflows

[nsalminen]

Optimize Github Action workflow execution efficiency by applying node_modules caching and precise path filters to the workflow checks. Also adds a testing step in the build workflow.

• Implement actions/cache@v4 to cache node_modules in build-check, lint-format-check, docs-build-check, and build-branch workflows.
• Add a npm run test step in the build-check workflow.
• Add path filters to build-check and lint-format-check to prevent unnecessary executions on unrelated assets.
• Constrain docs-build-check execution to documentation, core source, and configuration updates.

[ruofeidu]

Thank you Nels for optimizing the productivity!!

[dli7319]

IIUC, actions/setup-node@v6 is already supposed to do caching.
Is this not true?

[nsalminen]

IIUC, actions/setup-node@v6 is already supposed to do caching. Is this not true?

@dli7319 As far as I know, actions/setup-node only caches global package tarballs to save download time, but still runs npm ci on every build. That unzipping, linking, and post-install execution adds about 45 seconds of runner overhead. The two methods are complementary: setup-node optimizes network downloads on cache misses, while our actions/cache setup restores node_modules instantly on cache hits, skipping the install step entirely.

[dli7319]

Good find!