ci: run selinux and ostree unit tests

Add the new ostree and selinux unit tests to the github action CI

.github/workflows/tests.yml

@@ -79,6 +79,16 @@ jobs:
           cd osbuild
           python3 -m unittest -v test.test_osrelease
 
+      - name: Run test_util_ostree
+        run: |
+          cd osbuild
+          python3 -m unittest -v test.test_util_ostree
+
+      - name: Run test_util_selinux
+        run: |
+          cd osbuild
+          python3 -m unittest -v test.test_util_selinux
+
   rpm_build:
     name: "📦 RPM"
     runs-on: ubuntu-latest