[3.12] gh-130814: Enhance documentation for Python C API type objects (GH-130817) (#131224)

gh-130814: Enhance documentation for Python C API type objects (GH-130817)

The "Type Objects" title in `c-api/typeobj.rst`, duplicating the title of `c-api/type.rst`,
has been changed to "Type Objects Structures", thereby slightly improving Sphinx
search.
(cherry picked from commit 6b932edc5216d9766e70fef300a6b842ab33204c)

Co-authored-by: sharktide <meherrihaan@gmail.com>