[TASK] Raise typo3/testing-framework:^6.14.0

Brings a patch for extension testing, so they
don't inherit the composer flag for test instances
anymore.

composer req --dev typo3/testing-framework:^6.14.0

Change-Id: Ic0490cc888d08596cd7babfa7bd0247a885e29b9
Resolves: #95988
Releases: master
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/72183


Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>