[TASK] Simplify FE page generate lock strategy

With recent FE TS changes, we now have some information
a little earlier, which allows us to simplify the page
generation lock strategy a bit.

Until now, when two requests to the same page would still
generate different page cache entries due to different
TS condition verdicts, they block each other.

This is lifted: The page generation lock hash is
now identical to the page cache entry identifier,
requests only block each other if they really create
the same page cache entry.

Resolves: #98691
Related: #97816
Releases: main
Change-Id: Ie6b8c33f6df1d2da6e90456a7bb14d732c7e4ee7
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/76214


Tested-by: core-ci <typo3@b13.com>
Tested-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>