gh-99016: Make build scripts compatible with Python 3.8 (GH-99017)

Author: serhiy-storchaka

Misc/NEWS.d/next/Build/2022-11-02-19-25-07.gh-issue-99016.R05NkD.rst

@@ -0,0 +1 @@
+Fix build with ``PYTHON_FOR_REGEN=python3.8``.

Tools/build/generate_levenshtein_examples.py

@@ -1,7 +1,7 @@
 """Generate 10,000 unique examples for the Levenshtein short-circuit tests."""
 
 import argparse
-from functools import cache
+from functools import lru_cache
 import json
 import os.path
 from random import choices, randrange
@@ -22,7 +22,7 @@ def _substitution_cost(ch_a, ch_b):
     return _MOVE_COST
 
 
-@cache
+@lru_cache(None)
 def levenshtein(a, b):
     if not a or not b:
         return (len(a) + len(b)) * _MOVE_COST

Tools/build/generate_opcode_h.py

@@ -108,7 +108,7 @@ def main(opcode_py, outfile='Include/opcode.h', internaloutfile='Include/interna
     opname_including_specialized[255] = 'DO_TRACING'
     used[255] = True
 
-    with (open(outfile, 'w') as fobj, open(internaloutfile, 'w') as iobj):
+    with open(outfile, 'w') as fobj, open(internaloutfile, 'w') as iobj:
         fobj.write(header)
         iobj.write(internal_header)