There are no uses of jquery.ui.spinner in our repos (https://github.com/search?q=org%3Awikimedia+%22jquery.ui.spinner%22&type=Code) or on-wiki:
mwgrep "jquery.ui.spinner" (total: 0, shown: 0)
The entire jquery.ui package is already deprecated.
Timeline:
- Deprecate in MW 1.31 (LTS).
- Remove in MW 1.33.