Fix CI dependency cache

Author: tvdijen

.github/workflows/php.yml

@@ -81,7 +81,7 @@ 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-
 
@@ -147,7 +147,7 @@ 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-
 
@@ -188,7 +188,7 @@ 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-
 
@@ -246,7 +246,7 @@ 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-