chore(deps): update actions/checkout action to v6

Author: renovate[bot]

.github/workflows/code-style.yml

@@ -27,7 +27,7 @@ jobs:
                   git config --global core.eol lf
 
             - name: Checkout
-              uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
 
             - name: Install PHP
               uses: shivammathur/setup-php@v2

.github/workflows/mutation-tests.yml

@@ -29,7 +29,7 @@ jobs:
                   git config --global core.eol lf
 
             - name: Checkout
-              uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
 
             - name: Install PHP
               uses: shivammathur/setup-php@v2

.github/workflows/prettier.yml

@@ -11,7 +11,7 @@ jobs:
 
         steps:
             - name: Checkout
-              uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
 
             - name: Install the Nix package manager
               uses: cachix/install-nix-action@v31

.github/workflows/release.yaml

@@ -15,7 +15,7 @@ jobs:
 
         steps:
             - name: Checkout
-              uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
 
             - name: Determine tag
               id: tag_name

.github/workflows/static-analysis.yml

@@ -27,7 +27,7 @@ jobs:
                   git config --global core.eol lf
 
             - name: Checkout
-              uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
 
             - name: Install PHP
               uses: shivammathur/setup-php@v2

.github/workflows/tests.yml

@@ -17,7 +17,7 @@ jobs:
         outputs:
             version: ${{ steps.supported-versions-matrix.outputs.version }}
         steps:
-            - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+            - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
             - id: supported-versions-matrix
               uses: WyriHaximus/github-action-composer-php-versions-in-range@v1
     tests:
@@ -37,7 +37,7 @@ jobs:
                   git config --global core.eol lf
 
             - name: Checkout
-              uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
 
             - name: Install PHP
               uses: shivammathur/setup-php@v2