ginkgolinter: forbid focus container

Enable the new ginkgolinter rule to disallow using of focus containers
(e.g. `FIt`, `FContext` and so on). This will prevent leaking of debug
code from a local debug environment to the code base.

See more info here: https://github.com/nunnatsa/ginkgolinter#focus-container--focus-individual-spec-found-bug

Signed-off-by: Nahshon Unna-Tsameret <nunnatsa@redhat.com>

.golangci.yml

@@ -59,6 +59,8 @@ linters:
 linters-settings:
   gci:
     local-prefixes: "sigs.k8s.io/cluster-api"
+  ginkgolinter:
+    forbid-focus-container: true
   godot:
     #   declarations - for top level declaration comments (default);
     #   toplevel     - for top level comments;