The Lint CI job runs `prettier --check "**/*.md"` repo-wide. Reformat the
files it flags: doctrine-filters.md and upgrade-guide.md (prose wrap +
table alignment on recently merged content) plus the pre-existing
serialization.md and state-providers.md so the gate goes green.

Co-authored-by: Nozarashi <15169250+nozarashi20@users.noreply.github.com>
Co-authored-by: Maxime Valin <bysplashgm@gmail.com>
Co-authored-by: Gourab Sahu <grv_sh@yahoo.co.in>
Co-authored-by: Leighton Thomas <leightonthomas@users.noreply.github.com>

Co-authored-by: cay89 <cay89@users.noreply.github.com>

Record the ancestry discarded when #2325 was squash-merged, so future merge-ups use the correct merge base.

* docs(content-negotiation): document 4.4 charset change

Since 4.4 (core #8226), Content-Type only gets `; charset=utf-8`
for text/* and application/xml; JSON-family media types no longer
carry it. Verified against formatContentType() in
src/State/Util/HttpResponseHeadersTrait.php at upstream/4.4.

* docs(serialization): drop unreachable Symfony <=6.4 branch

Symfony floor is ^7.4 || ^8.0 since core #8397 (verified in
src/Symfony/composer.json at upstream/4.4), so the annotations
branch is unreachable and the >=7.0 branch is unconditional.
Collapse both into a single attributes-only instruction.

* docs(getting-started): state PHP/Symfony version floor

No page stated the supported versions. Add PHP >=8.2 and
Symfony ^7.4 || ^8.0, taken from composer.json and
src/Symfony/composer.json at upstream/4.4.

Core PR #8448 (cd67e0b23) adds the access_decision variable to security
expressions and AccessDecision::getMessage(); document how a voter's
reason reaches the client and that it is gated by kernel.debug. Also add
a usage example for ApiPlatform\Metadata\Exception\AccessDeniedException
(F22), the class the upgrade guide already points to.

…#2341)

…d is read (#2350)