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]>

Author: dependabot[bot]

.github/workflows/docs.yaml

@@ -60,7 +60,7 @@ jobs:
 
       - name: ⬇ Checkout docs.octoprint.org
         if: github.event_name == 'push' || github.event_name == 'workflow_dispatch' || github.event.client_payload.ref == format('refs/{0}/{1}', matrix.source, matrix.version)
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           path: docs.octoprint.org
 
@@ -94,7 +94,7 @@ jobs:
 
       - name: ⬇ Checkout OctoPrint
         if: github.event_name == 'push' || github.event_name == 'workflow_dispatch' || github.event.client_payload.ref == format('refs/{0}/{1}', matrix.source, matrix.version)
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           repository: "OctoPrint/OctoPrint"
           ref: ${{ matrix.version }}
@@ -143,7 +143,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: ⬇ Checkout docs.octoprint.org
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           ref: gh-pages
           path: docs