Bump actions/checkout from 2 to 3.1.0

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 3.1.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](https://github.com/actions/checkout/compare/v2...v3.1.0)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/pr.yml

@@ -14,7 +14,7 @@ jobs:
       with:
         go-version: 1.17
     - name: checkout
-      uses: actions/checkout@v3
+      uses: actions/checkout@v3.1.0
     - name: cache
       uses: actions/cache@v3
       with:
@@ -32,7 +32,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v3.1.0
       - name: lint
         uses: golangci/golangci-lint-action@v3.2.0
         continue-on-error: true