refactor: eliminate common-cache, use actions/cache directly

Replace common-cache wrapper with native actions/cache in npm-publish
and php-composer, completing the caching optimization campaign.

Changes:
1. npm-publish (lines 107-114):
   - Replace common-cache with actions/cache@v4.3.0
   - Use hashFiles() for node_modules cache key
   - Support multiple lock files (package-lock, yarn.lock, pnpm, bun)

2. php-composer (lines 177-190):
   - Replace common-cache with actions/cache@v4.3.0
   - Use multiline YAML for cleaner path configuration
   - Use hashFiles() for composer cache key
   - Support optional cache-directories input

Benefits:
- Native GitHub Actions functionality (no wrapper overhead)
- Better performance (no extra action call)
- Simpler maintenance (one less internal action)
- Standard approach used by official actions
- Built-in hashFiles() more efficient than manual sha256sum

Result:
- Eliminates all common-cache usage (reduced from 4 to 0 actions)
- common-cache action can now be deprecated/removed
- Completes caching optimization: 11 → 0 common-cache dependencies

Campaign summary:
- Phase 1: Inline language-version-detect
- Phase 2: Migrate 6 actions to setup-* native caching
- Phase 3: Replace go-lint common-cache with actions/cache
- Phase 4: Eliminate remaining common-cache (npm, php)

npm-publish/action.yml

@@ -106,12 +106,13 @@ runs:
 
     - name: Cache Node Dependencies
       id: cache
-      uses: ivuorinen/actions/common-cache@0fa9a68f07a1260b321f814202658a6089a43d42
+      uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4.3.0
       with:
-        type: 'npm'
-        paths: 'node_modules'
-        key-files: 'package-lock.json,yarn.lock,pnpm-lock.yaml,bun.lockb'
-        key-prefix: 'npm-publish-${{ steps.node-setup.outputs.package-manager }}'
+        path: node_modules
+        key: ${{ runner.os }}-npm-publish-${{ steps.node-setup.outputs.package-manager }}-npm-${{ hashFiles('package-lock.json', 'yarn.lock', 'pnpm-lock.yaml', 'bun.lockb') }}
+        restore-keys: |
+          ${{ runner.os }}-npm-publish-${{ steps.node-setup.outputs.package-manager }}-npm-
+          ${{ runner.os }}-npm-publish-${{ steps.node-setup.outputs.package-manager }}-
 
     - name: Install Dependencies
       if: steps.cache.outputs.cache-hit != 'true'