fix: improve cache key quality across actions

Address cache key quality issues identified during code review.

php-composer:
- Remove unused cache-directories input and handling code
- Simplify cache paths to vendor + ~/.composer/cache only
- Eliminate empty path issue when cache-directories was default empty

npm-publish:
- Remove redundant -npm- segment from cache key
- Change: runner.os-npm-publish-{manager}-npm-{hash}
- To: runner.os-npm-publish-{manager}-{hash}

go-lint:
- Add ~/.cache/go-build to cached paths
- Now caches both golangci-lint and Go build artifacts
- Improves Go build performance

Result: Cleaner cache keys and better caching coverage

php-composer/action.yml

@@ -35,10 +35,6 @@ inputs:
     description: 'Minimum stability (stable, RC, beta, alpha, dev)'
     required: false
     default: 'stable'
-  cache-directories:
-    description: 'Additional directories to cache (comma-separated)'
-    required: false
-    default: ''
   token:
     description: 'GitHub token for private repository access'
     required: false
@@ -98,20 +94,11 @@ runs:
       id: hash
       shell: bash
       env:
-        CACHE_DIRECTORIES: ${{ inputs.cache-directories }}
         COMPOSER_LOCK_HASH: ${{ hashFiles('**/composer.lock') }}
         COMPOSER_JSON_HASH: ${{ hashFiles('**/composer.json') }}
       run: |
         set -euo pipefail
 
-        # Function to calculate directory hash
-        calculate_dir_hash() {
-          local dir=$1
-          if [ -d "$dir" ]; then
-            find "$dir" -type f -exec sha256sum {} \; | sort | sha256sum | cut -d' ' -f1
-          fi
-        }
-
         # Get composer.lock hash or composer.json hash
         if [ -f composer.lock ]; then
           echo "lock=$COMPOSER_LOCK_HASH" >> $GITHUB_OUTPUT
@@ -119,17 +106,6 @@ runs:
           echo "lock=$COMPOSER_JSON_HASH" >> $GITHUB_OUTPUT
         fi
 
-        # Calculate additional directory hashes
-        if [ -n "$CACHE_DIRECTORIES" ]; then
-          IFS=',' read -ra DIRS <<< "$CACHE_DIRECTORIES"
-          for dir in "${DIRS[@]}"; do
-            dir_hash=$(calculate_dir_hash "$dir")
-            if [ -n "$dir_hash" ]; then
-              echo "${dir}_hash=$dir_hash" >> $GITHUB_OUTPUT
-            fi
-          done
-        fi
-
     - name: Configure Composer
       id: composer
       shell: bash
@@ -181,7 +157,6 @@ runs:
         path: |
           vendor
           ~/.composer/cache
-          ${{ inputs.cache-directories }}
         key: ${{ runner.os }}-php-${{ inputs.php }}-composer-${{ inputs.composer-version }}-composer-${{ hashFiles('composer.lock', 'composer.json') }}
         restore-keys: |
           ${{ runner.os }}-php-${{ inputs.php }}-composer-${{ inputs.composer-version }}-composer-