[BUGFIX] Allow file links in siteConfiguration/static-route

During the migration to the specific TCA type `link`
with #97159 the allowed link types for the field in
the siteConfiguration->static-routes have been added
incorrectly.

This change re-adds the file link-type as allowed
link type to that field.

Resolves: #101837
Related: #97159
Releases: main, 12.4
Change-Id: Iee40a86fe115749482c2aa0faa2c887adb4d025b
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/80847


Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Stefan Bürk <stefan@buerk.tech>