fix(ci): remove hardcoded branch filters from test-plugins.yml trigger

The push and pull_request triggers were locked to `main` and
`fix/ci-type-errors-and-stale-test-date`. Any new fix branch was
invisible to CI — exactly the pattern seen in PRs #22, #23, #28, #31
where only GitGuardian ran, not the actual test suite.

Remove the `branches` list entirely so CI fires on any branch/PR that
touches the relevant paths. Path filters still limit noise to changes
that actually affect plugins, claudeup-core, or the marketplace config.

Author: erudenko

.github/workflows/test-plugins.yml

@@ -2,7 +2,6 @@ name: Test Plugins
 
 on:
   push:
-    branches: [main, fix/ci-type-errors-and-stale-test-date]
     paths:
       - 'tools/claudeup-core/**'
       - 'tools/pnpm-lock.yaml'
@@ -14,7 +13,6 @@ on:
       - 'scripts/sync-shared-deps.sh'
       - '.github/workflows/test-plugins.yml'
   pull_request:
-    branches: [main, fix/ci-type-errors-and-stale-test-date]
     paths:
       - 'tools/claudeup-core/**'
       - 'tools/pnpm-lock.yaml'