workflows: build-numpy: trigger only on changes to workflow

Don't trigger the build-numpy.yml workflow if a change has been made
to other files, such as doc update scripts or documentation itself.

Signed-off-by: Trevor Gamblin <tgamblin@baylibre.com>

Author: threexc

.github/workflows/build-numpy.yml

@@ -11,9 +11,6 @@ on:
   pull_request:
     paths:
       - '.github/workflows/build-numpy.yml'
-      - 'actions/publish-to-gitlab/**'
-      - 'actions/publish-wheels/**'
-      - 'ci_scripts/update_doc.py'
 
 concurrency:
   group: ${{ github.workflow }}-${{ inputs.version || '2.5.1' }}-${{ github.head_ref || github.run_id }}