[BUGFIX] Make fixture invalid for symfony yaml parser

Resolves: #83239
Releases: master, 8.7
Change-Id: I3a617b31f197b19231a858f88f992904c681124d
Reviewed-on: https://review.typo3.org/54942


Reviewed-by: Carlos Meyer <cm@davitec.de>
Tested-by: Carlos Meyer <cm@davitec.de>
Reviewed-by: Bjoern Jacob <bjoern.jacob@tritum.de>
Tested-by: Bjoern Jacob <bjoern.jacob@tritum.de>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Mathias Brodala <mbrodala@pagemachine.de>
Tested-by: Mathias Brodala <mbrodala@pagemachine.de>
Reviewed-by: Susanne Moog <susanne.moog@typo3.org>
Tested-by: Susanne Moog <susanne.moog@typo3.org>

typo3/sysext/form/Tests/Unit/Mvc/Configuration/Fixtures/Invalid.yaml

-key
-  yek
\ No newline at end of file
+key:
+  yek
+ kye
\ No newline at end of file