The importmap tag `backend.contextmenu` was added to EXT:form
because it registers a context-menu item provider (for files).
It turns out that the provider is based on the EXT:filelist
provider and therefore doesn't require own javascript
(`@typo3/filelist/context-menu-actions` is used).

Resolves: #101445
Releases: main, 12.4
Change-Id: Ibdce39c971aae69889849b52847f62ce1298baf7
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/80216


Tested-by: core-ci <typo3@b13.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>