[3.10] gh-93738: Documentation C syntax (:c:type:`PyInterpreterState *` -> :c:expr:`PyInterpreterState *`) (GH-97777) (#97877)

:c:type:`PyInterpreterState *` -> :c:expr:`PyInterpreterState *`
(cherry picked from commit 4ebb0250314b57637d213cd5bc5f5ce5dd911d94)

Co-authored-by: Adam Turner <9087854+AA-Turner@users.noreply.github.com>