kata-deploy-push: only run if PR modifying tools path

Since we are using this to exercise any changes to osbuilder or
packaging scripts, let's make sure that we only run the test in that
case.

Similarly, don't run for every single push. Just run this workflow for
pull requests.

Fixes: #3594

Signed-off-by: Eric Ernst <eric_ernst@apple.com>

.github/workflows/kata-deploy-push.yaml

@@ -9,7 +9,9 @@ on:
       - synchronize
       - labeled
       - unlabeled
-  push:
+    paths:
+      - tools/**
+      - versions.yaml
 
 jobs:
   build-asset: