- Update dotnet version from 7 to 8 in GitHub unit test workflow.

- Update GitHub actions to latest major version due to deprecation of older Node.js version.

.github/workflows/pull-request.yml

@@ -7,12 +7,12 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        dotnet-version: ["7.0.x"]
+        dotnet-version: ["8.0.x"]
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Setup .NET Core SDK ${{ matrix.dotnet-version }}
-        uses: actions/setup-dotnet@v3
+        uses: actions/setup-dotnet@v4
         with:
           dotnet-version: ${{ matrix.dotnet-version }}
       - name: Install dependencies