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] <[email protected]>

.github/workflows/docker-pi-hole-base.yml

@@ -28,7 +28,7 @@ jobs:
     steps:
       -
         name: Checkout Repo
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       -
         name: Set up QEMU
         uses: docker/setup-qemu-action@v2

.github/workflows/ftl-build.yml

@@ -50,7 +50,7 @@ jobs:
     steps:
       -
         name: Checkout Repo
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       -
         name: Docker meta (Docker Hub and GitHub Container Registry)
         id: meta
@@ -149,7 +149,7 @@ jobs:
     steps:
       -
         name: Checkout Repo
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       -
         name: Download digests
         uses: actions/download-artifact@v3