[TASK] Avoid always empty removeChars in IS Lexer

Lexer->lexerConf['removeChars'] is always empty
since #93401. Remove it.

Resolves: #103551
Related: #93401
Releases: main
Change-Id: Ia5fab84836237e5c06e6c045ce5e4d34f085dc9b
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/83689


Tested-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>