[TASK] Remove unnecessary typecasts in ext:fluid

This change removes redundant typecasts in ext:fluid, where
the variable type already matches the type being cast.

Resolves: #104122
Releases: main
Change-Id: I9ff2f0eaeae1f931179dcfe85c99d877e67dd132
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/84728


Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Jasmina Ließmann <minapokhalo+typo3@gmail.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Jasmina Ließmann <minapokhalo+typo3@gmail.com>