[TASK] isPackageActive(): test light cond. first

The return should test for:
- isset($this->runtimeActivatedPackages[$packageKey]);
before it tests for:
- parent::isPackageActive($packageKey)

Change-Id: Ia18fb601a83e717c9bbf498eaa38c4cae04ceac6
Resolves: #55749
Releases: 6.2
Reviewed-on: https://review.typo3.org/27391
Reviewed-by: Oliver Klee
Reviewed-by: Christian Kuhn
Tested-by: Christian Kuhn
Reviewed-by: Markus Klein
Tested-by: Markus Klein