Remove modifies/frontend from labeler (go-gitea#30198)

Remove this label, I find it barely useful and we already have more
useful labels like `modifies/js`. Backport so that we can eventually
delete that label.

Co-authored-by: Giteabot <[email protected]>

Author: silverwind

.github/labeler.yml

@@ -4,13 +4,6 @@ modifies/docs:
           - "**/*.md"
           - "docs/**"
 
-modifies/frontend:
-  - changed-files:
-      - any-glob-to-any-file:
-          - "web_src/**"
-          - "tailwind.config.js"
-          - "webpack.config.js"
-
 modifies/templates:
   - changed-files:
       - all-globs-to-any-file: