Bump actions/checkout from 3 to 4 (#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>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/ci.yml

@@ -8,7 +8,7 @@ jobs:
       matrix:
         config: [Release, Debug]
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Fetch nuget packages
         run: dotnet restore
       - name: Add msbuild to PATH

.github/workflows/publish-release-to-otd.yml

@@ -8,13 +8,13 @@ jobs:
     name: Publish to OTD Plugin-Repository
     runs-on: windows-2022
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         name: Checkout ${{github.repository}}
         with:
           path: source
           fetch-depth: 0
           ref: master
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
         name: Checkout OpenTabletDriver/Plugin-Repository
         with:
           repository: OpenTabletDriver/Plugin-Repository