build(deps): 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](https://github.com/actions/checkout/compare/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/publish.yml

@@ -19,7 +19,7 @@ jobs:
         name: DNS
         runs-on: ubuntu-latest
         steps:
-            - uses: actions/checkout@v3
+            - uses: actions/checkout@v4
 
             - run: echo '{"cloudflare":{"TYPE":"CLOUDFLAREAPI","apitoken":"$CLOUDFLARE_API_TOKEN"}}' > ./creds.json
 

.github/workflows/validation.yml

@@ -21,7 +21,7 @@ jobs:
         name: DNS
         runs-on: ubuntu-latest
         steps:
-            - uses: actions/checkout@v3
+            - uses: actions/checkout@v4
 
             - name: Check
               uses: koenrh/dnscontrol-action@v3
@@ -33,7 +33,7 @@ jobs:
         name: JSON
         runs-on: ubuntu-latest
         steps:
-            - uses: actions/checkout@v3
+            - uses: actions/checkout@v4
 
             - name: JSON Syntax Check
               uses: limitusus/json-syntax-check@v2