[BUGFIX] Use `form-select` for EXT:form "version2" select elements

The EXT:form "version2" is using bootstrap 5,
which requires <select> elements to use the
`form-select` class. This is now fixed for
corresponding form elements.

Resolves: #103117
Releases: main, 12.4
Change-Id: I712cecfa4c5ac8facc84bc3cf0f742867ecc9613
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/82976


Reviewed-by: Oliver Bartsch <bo@cedev.de>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Oliver Bartsch <bo@cedev.de>