* main: (263 commits)
  bpo-45521: Fix a bug in the obmalloc radix tree code. (pythonGH-29051)
  bpo-45522: Allow to disable freelists on build time (pythonGH-29056)
  bpo-34451: Document prompt and output toggle feature in html tutorial (pythonGH-27105)
  bpo-44019: Add operator.call() to __all__ for the operator module (pythonGH-29110)
  bpo-45315: PyType_FromSpec: Copy spec->name and have the type own the memory for its name (pythonGH-29103)
  bpo-44220: Export PyStructSequence_UnnamedField in the limited API (pythonGH-26331)
  bpo-44174: [Enum] add reference to name mangling (pythonGH-29116)
  bpo-45548: add some missing entries to `Modules/Setup` (pythonGH-29115)
  bpo-35673: Add a public alias for namespace package __loader__ attribute (python#29049)
  bpo-45192: Fix a bug that infers the type of an os.PathLike[bytes] object as str (pythonGH-28323)
  bpo-45527: Don't count cache hits, just misses. (pythonGH-29092)
  bpo-45320: Remove long-deprecated inspect methods (pythonGH-28618)
  bpo-41374: Remove obsolete exclusion of netinet/tcp.h on Cygwin (pythonGH-21649)
  bpo-45532: Replace 'default' with 'main' as default in sys.version (pythonGH-29100)
  bpo-45464: [doc] Explain that subclassing multiple exceptions is fragile (pythonGH-29094)
  Cleanup a couple of comments left on PR 28775 post-merge. (pythonGH-29079)
  bpo-45536: Check OpenSSL APIs in configure (pythonGH-29088)
  Add PEPs 593 & 647 to list of PEPs at top of typing docs (pythonGH-29097)
  Add a comment about how to fix bogus test_host_resolution_bad_address failures (python#29085)
  bpo-44525: Specialize simple Python calls. (pythonGH-29033)
  ...