ci: use Cysharp/Actions checkout instead of 3rd party directly

Author: guitarrapc

.github/workflows/build-debug.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: Cysharp/Actions/.github/actions/checkout@main
       - uses: Cysharp/Actions/.github/actions/setup-dotnet@main
       - run: dotnet build -c Debug
       - run: dotnet test -c Debug --no-build
@@ -39,7 +39,7 @@ jobs:
           UNITY_PASSWORD: "op://${{ vars.OP_VAULT_ACTIONS_PUBLIC }}/UNITY_LICENSE/credential"
           UNITY_SERIAL: "op://${{ vars.OP_VAULT_ACTIONS_PUBLIC }}/UNITY_LICENSE/serial"
 
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: Cysharp/Actions/.github/actions/checkout@main
 
       # Run SourceGenerater to generate serialization code
       - uses: Cysharp/Actions/.github/actions/setup-dotnet@main

.github/workflows/build-release.yml

@@ -28,7 +28,7 @@ jobs:
     timeout-minutes: 10
     steps:
       - run: echo ${{ needs.update-packagejson.outputs.sha }}
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: Cysharp/Actions/.github/actions/checkout@main
         with:
           ref: ${{ needs.update-packagejson.outputs.sha }}
       - uses: Cysharp/Actions/.github/actions/setup-dotnet@main
@@ -62,7 +62,7 @@ jobs:
           UNITY_SERIAL: "op://${{ vars.OP_VAULT_ACTIONS_PUBLIC }}/UNITY_LICENSE/serial"
 
       - run: echo ${{ needs.update-packagejson.outputs.sha }}
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: Cysharp/Actions/.github/actions/checkout@main
         with:
           ref: ${{ needs.update-packagejson.outputs.sha }}