gh-90699: Use module state to access insert str object.

[corona10]

import pyperf runner = pyperf.Runner() runner.timeit(name="bench bisect", stmt=""" bisect.insort(a, 30) """, setup = """  import bisect  class A(list):  pass  a = A(range(1000)) """ )

Mean +- std dev: [main] 1.14 us +- 0.01 us -> [module] 1.06 us +- 0.01 us: 1.07x faster

[corona10]

Raised RLIMIT_NOFILE: 256 -> 1024 0:00:00 load avg: 5.14 Run tests sequentially 0:00:00 load avg: 5.14 [1/1] test_bisect beginning 6 repetitions 123456 ...... == Tests result: SUCCESS == 1 test OK. Total duration: 210 ms Tests result: SUCCESS