bpo-39573: Use Py_TYPE() macro in Objects directory

[vstinner]

Replace direct access to PyObject.ob_type with Py_TYPE().

https://bugs.python.org/issue39573

[codecov]

Codecov Report

Merging #18392 into master will decrease coverage by 0.05%.
The diff coverage is n/a.

@@ Coverage Diff @@## master #18392 +/- ##
==========================================
- Coverage 83.24% 83.19% -0.06% 
==========================================
Files 1570 1570 Lines 414397 414397 Branches 44429 44429 ==========================================
- Hits 344979 344755 -224 - Misses 59767 59995 +228 + Partials 9651 9647 -4 

Impacted Files	Coverage Δ
Lib/distutils/tests/test_bdist_rpm.py	30.00% <0.00%> (-65.00%)	⬇️
Lib/distutils/command/bdist_rpm.py	7.63% <0.00%> (-56.88%)	⬇️
Lib/test/test_urllib2net.py	76.92% <0.00%> (-13.85%)	⬇️
Lib/test/test_smtpnet.py	78.57% <0.00%> (-7.15%)	⬇️
Lib/ftplib.py	63.85% <0.00%> (-6.06%)	⬇️
Lib/test/test_ftplib.py	87.11% <0.00%> (-4.72%)	⬇️
Tools/scripts/db2pickle.py	17.82% <0.00%> (-3.97%)	⬇️
Tools/scripts/pickle2db.py	16.98% <0.00%> (-3.78%)	⬇️
Lib/test/test_socket.py	71.94% <0.00%> (-3.77%)	⬇️
Lib/test/test_asyncio/test_base_events.py	91.84% <0.00%> (-3.30%)	⬇️
... and 51 more

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