Add PHP nightly build to test matrix

Author: flavioheleno

.github/workflows/continuous-integration.yml

@@ -21,11 +21,18 @@ jobs:
       fail-fast: false
       matrix:
         php-version:
-          - "8.1"
-          - "8.2"
-          - "8.3"
+          - '8.1'
+          - '8.2'
+          - '8.3'
         dependency-version: [prefer-lowest, prefer-stable]
         experimental: [false]
+        include:
+          - php-version: '8.4'
+            dependency-version: prefer-lowest
+            experimental: true
+          - php-version: '8.4'
+            dependency-version: prefer-stable
+            experimental: true
 
     steps:
     - uses: actions/checkout@v3
@@ -48,8 +55,8 @@ jobs:
       uses: actions/cache@v3
       with:
         path: ${{ steps.composer-cache.outputs.dir }}
-        key: ${{ runner.os }}-php-${{ matrix.php-version }}-${{ hashFiles('**/composer.lock') }}
-        restore-keys: ${{ runner.os }}-php-${{ matrix.php-version }}-
+        key: ${{ runner.os }}-php-${{ matrix.php-version }}-composer-${{ matrix.prefer }}-${{ hashFiles('**/composer.json') }}
+        restore-keys: ${{ runner.os }}-php-${{ matrix.php-version }}-composer-${{ matrix.prefer }}
 
     - name: Install dependencies (PHP 8)
       if: steps.composer-cache.outputs.cache-hit != 'true' && matrix.php-version >= 8