Bump actions/checkout from 2.3.4 to 3.1.0

Bumps [actions/checkout](https://github.com/actions/checkout) from 2.3.4 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/v2.3.4...v3.1.0)

---
updated-dependencies:
- dependency-name: actions/checkout
  dependency-type: direct:production
  update-type: version-update:semver-major
...
Signed-off-by: Ndependabot[bot] <support@github.com>

.github/workflows/backup.yaml

@@ -10,7 +10,7 @@ jobs:
   BackupGit:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2.3.4
+    - uses: actions/checkout@v3.1.0
     - name: Backup to Gitee
       uses: jenkins-zh/git-backup-actions@v0.0.4
       env:

.github/workflows/pull-request.yaml

@@ -16,7 +16,7 @@ jobs:
           go-version: 1.13
         id: go
       - name: Check out code into the Go module directory
-        uses: actions/checkout@v2.3.4
+        uses: actions/checkout@v3.1.0
       - name: Run GoReleaser
         uses: goreleaser/goreleaser-action@v2.4.1
         with:

.github/workflows/release.yaml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout
-      uses: actions/checkout@v2.3.4
+      uses: actions/checkout@v3.1.0
     - name: Unshallow
       run: git fetch --prune --unshallow
     - name: Set up Go