⬆️ Bump actions/checkout from 2 to 4

Bumps [actions/checkout](https://github.com/actions/checkout) from 2 to 4.
- [Release notes](https://github.com/actions/checkout/releases)
- [Changelog](https://github.com/actions/checkout/blob/main/CHANGELOG.md)
- [Commits](actions/checkout@v2...v4)

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

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/build.yml

@@ -33,7 +33,7 @@ jobs:
           fi
 
       - name: Check out code into the Go module directory
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Get dependencies
         run: |

.github/workflows/gh-pages.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout main
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
          ref: main
          path: src
@@ -30,7 +30,7 @@ jobs:
 #          publish_dir: ./gh-pages
 
       - name: Checkout gh-pages
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           ref: gh-pages
           path: docs

.github/workflows/release.yml

@@ -48,7 +48,7 @@ jobs:
           fi
 
       - name: Check out code into the Go module directory
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Get dependencies
         run: |

.github/workflows/test.yml

@@ -21,7 +21,7 @@ jobs:
         id: go
 
       - name: Check out code into the Go module directory
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
 
       - name: Get dependencies
         run: |