chore(deps): update actions/checkout action to v7

Author: renovate[bot]

.github/workflows/ci.yml

@@ -39,7 +39,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
 
       - name: Setup Python
         uses: actions/setup-python@v6
@@ -56,7 +56,7 @@ jobs:
     runs-on: ubuntu-24.04
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
 
       - name: Setup Python
         uses: actions/setup-python@v6
@@ -94,7 +94,7 @@ jobs:
           install: true
 
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
 
       # We ask Docker to use GitHub Action's native caching support to speed up
       # the build, per https://docs.docker.com/build/cache/backends/gha/.
@@ -134,7 +134,7 @@ jobs:
       - build
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@v7
 
       - name: Download Single-Platform Packages
         uses: actions/download-artifact@v8