[BUGFIX] Fix executable permissions on files

A large number of files were stored with executable permissions. This
may be a (minor) security risk and can be confusing. The patch removes
the executable permissions on all files but:

* typo3/cli_dispatch.phpsh
* typo3/cleaner_check.sh
* typo3/cleaner_fix.sh

Resolves: #56571
Releases: 6.2
Change-Id: Ib6a9fb19fe716d7d5405d5a7120b50269bdbf5f8
Reviewed-on: https://review.typo3.org/28072
Reviewed-by: Xavier Perseguers
Tested-by: Xavier Perseguers
Reviewed-by: Helmut Hummel
Tested-by: Helmut Hummel