Update CI file for new testing workflow

.github/workflows/run-tests.yml

@@ -17,10 +17,16 @@ on:
       - '.github/**'
 
 jobs:
-  build-and-test:
-    name: "Build and test"
-    uses: nfdi4plants/actions-workflows/.github/workflows/build-and-test-solution.yml@main
-    with:
-      solution: ./arc-validation-packages.sln
-      checkout-submodules: true
-      configuration: Release
+  build-and-test-linux:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+    - name: Setup .NET
+      uses: actions/setup-dotnet@v4
+      with:
+        dotnet-version: 8.x.x
+    - name: Build and test
+      working-directory: ./
+      run: dotnet test