make target-branch a regexp

so that the linter will run on all branches and not just main when for
example we are doing a backport test.

Signed-off-by: Chmouel Boudjnah <chmouel@redhat.com>

Author: chmouel

.tekton/linter.yaml

@@ -5,7 +5,7 @@ metadata:
   name: linters
   annotations:
     pipelinesascode.tekton.dev/on-event: "[push, pull_request]"
-    pipelinesascode.tekton.dev/on-target-branch: "[main]"
+    pipelinesascode.tekton.dev/on-target-branch: "[*]"
     pipelinesascode.tekton.dev/max-keep-runs: "2"
     pipelinesascode.tekton.dev/task: "[git-clone]"
 spec: