[BUGFIX] Wrong method call

During #46950 a wrong call extbase ExtensionUtility instead of core
ExtensionManagementUtility slipped through and is fixed by the patch.

Fixes: #47143
Related: #46950
Releases: 6.1

Change-Id: I0cfccc457c2c8990e26907c743d89b94a8e921d9
Reviewed-on: https://review.typo3.org/19812
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn