Update actions/checkout action to v7

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

Author: renovate[bot]

.github/workflows/ci.yml

@@ -20,7 +20,7 @@ jobs:
           - "8.4"
 
     steps:
-      - uses: "actions/checkout@v6"
+      - uses: "actions/checkout@v7"
       - uses: "shivammathur/setup-php@v2"
         with:
           coverage: "none"
@@ -47,7 +47,7 @@ jobs:
             code-coverage: "pcov"
 
     steps:
-      - uses: "actions/checkout@v6"
+      - uses: "actions/checkout@v7"
       - uses: "shivammathur/setup-php@v2"
         with:
           coverage: "${{ matrix.code-coverage }}"
@@ -82,7 +82,7 @@ jobs:
           - "8.4"
 
     steps:
-      - uses: "actions/checkout@v6"
+      - uses: "actions/checkout@v7"
       - uses: "shivammathur/setup-php@v2"
         with:
           coverage: "none"
@@ -101,7 +101,7 @@ jobs:
           - "8.4"
 
     steps:
-      - uses: "actions/checkout@v6"
+      - uses: "actions/checkout@v7"
       - uses: "shivammathur/setup-php@v2"
         with:
           coverage: "none"