Update actions/cache action to v6

| datasource  | package       | from | to     |
| ----------- | ------------- | ---- | ------ |
| github-tags | actions/cache | v5   | v6.1.0 |

Author: renovate[bot]

.github/workflows/coding-standard.yml

@@ -38,7 +38,7 @@ jobs:
               run: echo "::set-output name=dir::$(composer config cache-dir)"
 
             - name: Cache dependencies
-              uses: actions/cache@v5
+              uses: actions/cache@v6
               with:
                 path: ${{ steps.composer-cache.outputs.dir }}
                 key: composer-${{ runner.os }}-${{ matrix.php-version }}-${{ hashFiles('composer.*') }}-${{ matrix.dependencies }}

.github/workflows/infection.yml

@@ -39,7 +39,7 @@ jobs:
         run: echo "::set-output name=dir::$(composer config cache-dir)"
 
       - name: Cache dependencies
-        uses: actions/cache@v5
+        uses: actions/cache@v6
         with:
           path: ${{ steps.composer-cache.outputs.dir }}
           key: composer-${{ runner.os }}-${{ matrix.php-version }}-${{ hashFiles('composer.*') }}-${{ matrix.dependencies }}

.github/workflows/phpstan.yml

@@ -38,7 +38,7 @@ jobs:
               run: echo "::set-output name=dir::$(composer config cache-dir)"
 
             - name: Cache dependencies
-              uses: actions/cache@v5
+              uses: actions/cache@v6
               with:
                 path: ${{ steps.composer-cache.outputs.dir }}
                 key: composer-${{ runner.os }}-${{ matrix.php-version }}-${{ hashFiles('composer.*') }}-${{ matrix.dependencies }}

.github/workflows/phpunit.yml

@@ -45,7 +45,7 @@ jobs:
               run: echo "::set-output name=dir::$(composer config cache-dir)"
 
             - name: Cache dependencies
-              uses: actions/cache@v5
+              uses: actions/cache@v6
               with:
                 path: ${{ steps.composer-cache.outputs.dir }}
                 key: composer-${{ runner.os }}-${{ matrix.php-version }}-${{ hashFiles('composer.*') }}-${{ matrix.dependencies }}

.github/workflows/psalm.yml

@@ -38,7 +38,7 @@ jobs:
               run: echo "::set-output name=dir::$(composer config cache-dir)"
 
             - name: Cache dependencies
-              uses: actions/cache@v5
+              uses: actions/cache@v6
               with:
                 path: ${{ steps.composer-cache.outputs.dir }}
                 key: composer-${{ runner.os }}-${{ matrix.php-version }}-${{ hashFiles('composer.*') }}-${{ matrix.dependencies }}

.github/workflows/require-checker.yml

@@ -38,7 +38,7 @@ jobs:
               run: echo "::set-output name=dir::$(composer config cache-dir)"
 
             - name: Cache dependencies
-              uses: actions/cache@v5
+              uses: actions/cache@v6
               with:
                 path: ${{ steps.composer-cache.outputs.dir }}
                 key: composer-${{ runner.os }}-${{ matrix.php-version }}-${{ hashFiles('composer.*') }}-${{ matrix.dependencies }}