[BUGFIX] Flag compressed files to exclude from compression

Resolves: #58582
Related: #58010
Related: #57294
Releases: 6.2
Change-Id: I89e9bea10c24944ad2efb1fb9029ec75dc2f78db
Reviewed-on: https://review.typo3.org/29579
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters