[3.11] gh-90763: Modernise xx template module initialisation (GH-93078) (#93681)

Use C APIs such as PyModule_AddType instead of PyModule_AddObject.
Also remove incorrect module decrefs if module fails to initialise.
(cherry picked from commit a87c9b538fbfc42883417c4d5e69f1a5922690e3)

Co-authored-by: Erlend Egeberg Aasland <erlend.aasland@protonmail.com>