Problem/Motivation
We've forked jQuery UI components into core, but for now have left the version numbers unchanged.
See brief discussion at #3087685-43: Remove deprecated jQuery UI components and fork remaining source code into core and #3087685-44: Remove deprecated jQuery UI components and fork remaining source code into core.
Proposed resolution
Keep the jQuery version as 1.12.1 until we introduce a change to the source. Whenever we make a change to the sources, add an extra suffix string to the version:
Add a version string postfix starting with zero (to indicate non-release status), and increment the patch, minor, or major version as appropriate under semver depending on the types of changes needed to jQuery UI. Examples: 1.12.1+0.0.1, 1.12.1+0.1.0