ci: Run cockpit tests in PRs

See https://cockpit-project.org/blog/tmt-cross-project-testing.html

Drop the install-only tests, as TF only runs the default "install check"
test if there are no plans, but now we have one. That will cover the
installation/upgrade as preparation step.

.fmf/version

@@ -0,0 +1 @@
+1

packit.yaml

@@ -15,8 +15,18 @@ jobs:
     - fedora-development
     - fedora-latest-stable
 
+  # run tests for packages which test SELinux policy well, see plans/ with `revdeps == yes`
   - job: tests
+    identifier: revdeps
     trigger: pull_request
     targets:
     - fedora-development
     - fedora-latest-stable
+    tf_extra_params:
+      environments:
+        - artifacts:
+          - type: repository-file
+            id: https://copr.fedorainfracloud.org/coprs/g/cockpit/main-builds/repo/fedora-$releasever/group_cockpit-main-builds-fedora-$releasever.repo
+          tmt:
+            context:
+              revdeps: "yes"

plans/cockpit.fmf

@@ -0,0 +1,30 @@
+# reverse dependency test for https://github.com/cockpit-project/cockpit
+# if this fails in a non-obvious way, please contact the cockpit team in your PR for investigation:
+# @martinpitt, @marusak, @jelly
+
+enabled: false
+adjust+:
+  when: revdeps == yes
+  enabled: true
+
+discover:
+    how: fmf
+    url: https://github.com/cockpit-project/cockpit
+    ref: main
+execute:
+    how: tmt
+
+/basic:
+    summary: Run tests for basic packages
+    discover+:
+        test: /test/browser/basic
+
+/network:
+    summary: Run tests for cockpit-networkmanager
+    discover+:
+        test: /test/browser/network
+
+/optional:
+    summary: Run tests for optional packages
+    discover+:
+        test: /test/browser/optional