perf(eslint): enable caching for lint scripts and CI

[jhnns]

Summary

• Add --cache to every eslint CLI invocation in npm test scripts
• Git-ignore .eslintcache files locally while caching **/.eslintcache in CI
• Refresh the GitHub Actions eslint cache each run via restore-keys so subdirectory fixture caches are reused

Test plan

• Verified eslint --cache creates .eslintcache locally
• Verified .eslintcache is ignored by git in root and fixture test dirs
• CI passes on this PR

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/@peerigon/configs@227

commit: 3e07324

[Copilot]

Pull request overview

This PR improves linting performance in @peerigon/configs by enabling ESLint’s on-disk cache across local npm scripts and GitHub Actions, with CI configured to persist .eslintcache between runs.

Changes:

• Add --cache to all npm scripts that invoke eslint.
• Ignore .eslintcache files via .gitignore so local cache artifacts aren’t committed.
• Cache **/.eslintcache in GitHub Actions to reuse lint results across CI runs.

Reviewed changes

Copilot reviewed 2 out of 3 changed files in this pull request and generated 1 comment.

File	Description
package.json	Enables ESLint caching for all lint-related npm test scripts.
.gitignore	Ignores .eslintcache files to prevent committing generated cache artifacts.
.github/workflows/test-and-release.yml	Caches .eslintcache files across CI runs (including fixture subdirectories).

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