ci: fix get-changed-files

Ana06/get-changed-files@v1.1 is a fork of
https://github.com/jitterbit/get-changed-files, which supports
`pull_request_target` and allow to filter files using regular
expressions.

As we need to use `pull_request_target`, Ana06/get-changed-files@v1.1
works, but jitterbit/get-changed-files@v1 doesn't.

.github/workflows/changelog.yml

@@ -15,7 +15,7 @@ jobs:
     steps:
     - name: Get changed files
       id: files
-      uses: jitterbit/get-changed-files@v1
+      uses: Ana06/get-changed-files@v1.1
     - name: check changelog updated
       id: changelog_updated
       env: