[BUGFIX] Extension update fails if needed by other extensions

On update process the extension which should be updated gets
uninstalled. This doesn't work if the extension is needed by other ones.
This patch removes the unload process before the update to make sure
system is working in the mean time.

Resolves: #57264
Releases: 6.2
Change-Id: I6f54cf8ba977e9c8038790ea3857ba6fff61a5f9
Reviewed-on: https://review.typo3.org/28883
Reviewed-by: Cedric Ziel
Tested-by: Cedric Ziel
Reviewed-by: Markus Klein
Tested-by: Markus Klein