[BUGFIX] Re-enable button after save in ext:install

After saving the state of the feature toggles in ext:install,
the save button remains disabled.

This change fixes the problem.

Resolves: #100839
Releases: main, 12.4
Signed-off-by: Torben Hansen <derhansen@gmail.com>
Change-Id: I12607ada13646c8eb54df107cef6082d43cb5b9c
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/78967


Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Benni Mack <benni@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Thomas Hohn <tho@gyldendal.dk>