ci(behavior): always run on PRs targeting main and stable (#2960)

GitHub's required-status-check rule is name-based; when a workflow is
skipped by paths, the required check stays pending and blocks the PR
forever. That has been blocking dep-only and other path-irrelevant PRs
(e.g. #2949) on the Behavior Tests / validate gate.

The simplest durable fix is to drop the path filter and let the
workflow run on every PR. Trades a bounded amount of CI minutes for
removing an entire class of stuck-PR failures and the recurring
maintenance of keeping path lists in sync with the repo layout.

Author: caio-pizzol

.github/workflows/ci-behavior.yml

@@ -6,16 +6,6 @@ permissions:
 on:
   pull_request:
     branches: [main, stable]
-    paths:
-      - 'packages/superdoc/**'
-      - 'packages/layout-engine/**'
-      - 'packages/super-editor/**'
-      - 'packages/word-layout/**'
-      - 'packages/preset-geometry/**'
-      - 'tests/behavior/**'
-      - 'shared/**'
-      - '.github/workflows/ci-behavior.yml'
-      - '!**/*.md'
   merge_group:
   workflow_dispatch: