Bump actions/checkout from 3 to 4 (#94)

Bumps [actions/checkout](https://github.com/actions/checkout) from 3 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v3...v4)

---
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/pull-request.yaml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
     - name: Check out code
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
     - name: Set up QEMU
       uses: docker/setup-qemu-action@v3
 
@@ -23,7 +23,7 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
     - name: Check out code
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Unit Test
       run: make test
@@ -33,7 +33,7 @@ jobs:
     runs-on: ubuntu-20.04
     steps:
     - name: Check out code
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
 
     - name: Golang Style and Lint Check
       run: make check