Bump actions/checkout from 3 to 4

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] <support@github.com>

.github/workflows/builder.yaml

@@ -14,7 +14,7 @@ jobs:
     steps:
       -
         name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       -
         name: Docker meta
         id: meta

.github/workflows/unit.yml

@@ -13,7 +13,7 @@ jobs:
       matrix:
         go-version: [ '1.21' ]
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Setup Go
         uses: actions/setup-go@v4
         with: