Auto merge of #127127 - notriddle:notriddle/pulldown-cmark-0.11, r=GuillaumeGomez

rustdoc: update to pulldown-cmark 0.11

r? rustdoc

This pull request updates rustdoc to the latest version of pulldown-cmark. Along with adding new markdown extensions (which this PR doesn't enable), the new pulldown-cmark version also fixes a large number of bugs. Because all text files successfully parse as markdown, these bugfixes change the output, which can break people's existing docs.

A crater run, rust-lang/rust#121659, has already been run for this change.

The first commit upgrades and fixes rustdoc. The second commit adds a lint for the footnote and block quote parser changes, which break the largest numbers of docs in the Crater run. The strikethrough change was mitigated in pulldown-cmark itself.

Unblocks rust-lang/rust-clippy#12876

Author: bors