chore: bump actions/checkout from 2.3.4 to 2.4.0

Bumps [actions/checkout](https://github.com/actions/checkout) from 2.3.4 to 2.4.0.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v2.3.4...v2.4.0)

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

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

.github/workflows/push.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       -
-        uses: actions/checkout@v2.3.4
+        uses: actions/checkout@v2.4.0
       -
         name: lint
         uses: golangci/golangci-lint-action@v2.5.2
@@ -25,7 +25,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       -
-        uses: actions/checkout@v2.3.4
+        uses: actions/checkout@v2.4.0
       -
         uses: actions/setup-go@v2
       # we cannot use nancy-github-action because it is outdated, so it's better to use the latest
@@ -43,7 +43,7 @@ jobs:
     steps:
       -
         name: Checkout code
-        uses: actions/checkout@v2.3.4
+        uses: actions/checkout@v2.4.0
       -
         name: Get go.mod details
         uses: Eun/go-mod-details@v1.0.4