ci: add workflow test-all

Author: vojtechmares

.github/workflows/test-all.yml

@@ -0,0 +1,17 @@
+name: Test all (on all branches)
+
+on: [push]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: dotnet build
+        run: dotnet build
+
+      - name: dotnet test
+        run: dotnet test