[TASK] Change repository url for introduction package

Resolves: #55377
Releases: 6.1, 6.0, 4.7, 4.5
Change-Id: Ic22c1baf87b1cca9c6169b682aa629765fc1ab14
Reviewed-on: https://review.typo3.org/27084
Reviewed-by: Philipp Gampe
Tested-by: Philipp Gampe