Revert "Fix Dead link in README for 'assert statements' " (#9369)
Revert "Fix Dead link in README for 'assert statements' " (#9369)

This reverts commit 15989ddc8f20e49602858e6e4a2631b71e8b9ef1.

Reverts #8945, thus reintroducing #8926 temporarily, but we should be close to
the 7.0.0 release now, where this is the correct URL to use.

Closes #8831 as follow-up to #8858.
pytest-dev/pytest,markshao/pytest,Akasurde/pytest,RonnyPfannschmidt/pytest