[changelog skip] Fix Escaping in Changelog Script

The previous PR had a bug where the REGEX for grep was not properly escaped. This PR fixes that issue.

Author: schneems

.github/workflows/check_changelog.yml

@@ -9,4 +9,4 @@ jobs:
    - uses: actions/checkout@v1
    - name: Check that CHANGELOG is touched
      run: |
-       cat $GITHUB_EVENT_PATH | jq .pull_request.title |  grep -i '[((changelog skip)|(ci skip))]' ||  git diff remotes/origin/${{ github.base_ref }} --name-only | grep CHANGELOG.md
+       cat $GITHUB_EVENT_PATH | jq .pull_request.title |  grep -i '\[\(\(changelog skip\)\|\(ci skip\)\)\]' ||  git diff remotes/origin/${{ github.base_ref }} --name-only | grep CHANGELOG.md