Bump actions/checkout from 2 to 3 (contiv#70)

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 3.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v2...v3)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/go.yml

@@ -18,7 +18,7 @@ jobs:
   #     with:
   #       go-version: 1.15
   #   - name: Check-out code
-  #     uses: actions/checkout@v2
+  #     uses: actions/checkout@v3
   #   - name: Run unit tests
   #     run: |
   #       make test
@@ -67,7 +67,7 @@ jobs:
     runs-on: [ubuntu-latest]
     steps:
     - name: Check-out code
-      uses: actions/checkout@v2
+      uses: actions/checkout@v3
     - name: Run code linters
       run: |
         make golangci

.github/workflows/release.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: [ubuntu-latest]
     steps:
     - name: Check-out code
-      uses: actions/checkout@v2
+      uses: actions/checkout@v3
     - name: Read version
       run: |
         echo "version=$(head VERSION)" >> $GITHUB_ENV