Update actions/checkout action to v7

| datasource  | package          | from   | to     |
| ----------- | ---------------- | ------ | ------ |
| github-tags | actions/checkout | v6.0.3 | v7.0.0 |


Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/coding-standard.yml

@@ -26,7 +26,7 @@ jobs:
 
     steps:
       - name: "Checkout"
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
 
       - name: "Install PHP"
         uses: "shivammathur/setup-php@2.37.2"

.github/workflows/docs-check.yml

@@ -25,7 +25,7 @@ jobs:
 
         steps:
             - name: "Checkout"
-              uses: actions/checkout@v6
+              uses: actions/checkout@v7
 
             - name: "Install PHP"
               uses: "shivammathur/setup-php@2.37.2"

.github/workflows/mutation-tests-diff.yml

@@ -22,7 +22,7 @@ jobs:
 
         steps:
             - name: "Checkout"
-              uses: actions/checkout@v6
+              uses: actions/checkout@v7
               with:
                 fetch-depth: 0
 

.github/workflows/mutation-tests.yml

@@ -26,7 +26,7 @@ jobs:
 
         steps:
             - name: "Checkout"
-              uses: actions/checkout@v6
+              uses: actions/checkout@v7
 
             - name: "Install PHP"
               uses: "shivammathur/setup-php@2.37.2"

.github/workflows/phpstan.yml

@@ -26,7 +26,7 @@ jobs:
 
     steps:
       - name: "Checkout"
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
 
       - name: "Install PHP"
         uses: "shivammathur/setup-php@2.37.2"

.github/workflows/phpunit.yml

@@ -37,7 +37,7 @@ jobs:
             operating-system: "windows-latest"
     steps:
       - name: "Checkout"
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
 
       - name: "Install PHP"
         uses: "shivammathur/setup-php@2.37.2"

.github/workflows/release-on-milestone-closed-triggering-release-event.yml

@@ -18,7 +18,7 @@ jobs:
 
         steps:
             - name: "Checkout"
-              uses: actions/checkout@v6
+              uses: actions/checkout@v7
 
             - name: "Release"
               uses: "laminas/automatic-releases@v1"