bpo-45548: Add missing extensions to Modules/Setup (GH-29199)

Adds _ctypes, _decimal, _multiprocessing, _posixshmem, _scproxy, _sqlite3,
and _uuid.

Use Makefile variables to build OpenSSL and TCL/TK modules.

Drop ``-lm`` from math lines. Extensions are always linked against libm.

Signed-off-by: Christian Heimes <christian@python.org>