fix: stability is vary too

Author: joostdebruijn

.github/workflows/tests.yml

@@ -41,9 +41,9 @@ jobs:
       - uses: actions/cache@v3
         with:
           path: ${{ steps.composer-cache.outputs.dir }}
-          key: ${{ runner.os }}-${{ matrix.php }}-${{ matrix.laravel }}-${{ matrix.testbench }}-composer
+          key: ${{ runner.os }}-${{ matrix.php }}-${{ matrix.laravel }}-${{ matrix.testbench }}-${{ matrix.stability }}-composer
           restore-keys: |
-            ${{ runner.os }}-${{ matrix.php }}-${{ matrix.laravel }}-${{ matrix.testbench }}-composer
+            ${{ runner.os }}-${{ matrix.php }}-${{ matrix.laravel }}-${{ matrix.testbench }}-${{ matrix.stability }}-composer
 
       - name: Setup PHP
         uses: shivammathur/setup-php@v2