[BUGFIX] Avoid race condition in DI cache persistence

With #90418 the container cache has been excluded from the
regular cache-flush-pipeline.
Therefore flushing has been explicitly performed when writing a
new cache entry (with the intent to clean up old cache entries).

Issue is: Cleaning up the entire folder by deleting the folder means
a concurrent request – that is creating the same DI cache as well –
will fail to write the cache when the folder is (re)moved in that
moment.

It turns out this cache-flush is not needed at all, since the cache
identifier is stable for an TYPO3 instance, therefore a pre-flight
flush can be dropped.

Releases: main, 12.4, 11.5
Resolves: #103294
Change-Id: I1267d794291899e2b0d551b1725bd4a3354823bd
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/83261


Reviewed-by: Benjamin Franzke <ben@bnf.dev>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Benjamin Franzke <ben@bnf.dev>