[TASK] Revamp phpstan config and handling

We currently have the situation that phpstan is
hard to update and maintain due to the phpstan
config file that sets very specific rulesets.

This is unfortunate since phpstan tends to change
and rename rules at will.

The general usage API of phpstan is basically as
follows: Have a slim config file that sets the
basic level. Then maintain a 'baseline' file that
lists violations, using the --generate-baseline
command option. The todo job for people working
on phpstan errors is then to look at the baseline
file, pick up some issues, fix them, then re-generate
baseline. When baseline is small enough, the level
is raised, a new baseline is generated, and the
fix-job starts again.

The patch does exactly this: The existing config
is dropped and runTests.sh receives a command to
generate baseline.

With this in place, we can easily raise phpstan
to a PHP 8.1 compatible version:

> composer req friendsoftypo3/phpstan-typo3:"^0.9.0" --dev
> composer req phpstan/phpstan:"^1.4.3" --dev
> Build/Script/runTests.sh -s phpstanGenerateBaseline

This initialy adds about 4000 ignores to the baseline
with level 3, but we can reduce this drastically with
just a couple of dedicated patches, soon.

The config is heavily streamlined and for instance does
*not* ignore tests anymore, which actually finds a ton
of misuses and bugs within tests and classes.

Resolves: #96675
Releases: main, 11.5
Change-Id: I0e7ff7aa796e59a2c5eedde0b673f741f8b87dea
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/73037


Tested-by: core-ci <typo3@b13.com>
Tested-by: Daniel Goerz <daniel.goerz@posteo.de>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Daniel Goerz <daniel.goerz@posteo.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>