Fix CI dependency cache

Author: tvdijen

.github/workflows/php.yml

@@ -77,7 +77,7 @@ jobs:
       - name: Cache composer dependencies
         uses: actions/cache@v4
         with:
-          path: $COMPOSER_CACHE
+          path: ${{ env.COMPOSER_CACHE }}
           key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
           restore-keys: ${{ runner.os }}-composer-
 
@@ -139,7 +139,7 @@ jobs:
       - name: Cache composer dependencies
         uses: actions/cache@v4
         with:
-          path: $COMPOSER_CACHE
+          path: ${{ env.COMPOSER_CACHE }}
           key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
           restore-keys: ${{ runner.os }}-composer-
 
@@ -178,7 +178,7 @@ jobs:
       - name: Cache composer dependencies
         uses: actions/cache@v4
         with:
-          path: $COMPOSER_CACHE
+          path: ${{ env.COMPOSER_CACHE }}
           key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
           restore-keys: ${{ runner.os }}-composer-
 
@@ -232,7 +232,7 @@ jobs:
       - name: Cache composer dependencies
         uses: actions/cache@v4
         with:
-          path: $COMPOSER_CACHE
+          path: ${{ env.COMPOSER_CACHE }}
           key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
           restore-keys: ${{ runner.os }}-composer-