chore: update zizmor workflow triggers and permissions (#624)

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>

Author: wagoodman

.github/workflows/validate-github-actions.yaml

@@ -1,10 +1,8 @@
 name: "Validate GitHub Actions"
 
 on:
+  workflow_dispatch:
   pull_request:
-    paths:
-      - '.github/workflows/**'
-      - '.github/actions/**'
   push:
     branches:
       - main