test_wm_iconbitmap() timeout after 10 min on "macOS / build and test (macos-26-intel)" CI

Example of failure: https://github.com/python/cpython/actions/runs/23552862012/job/68571481619?pr=146357

(...)
test_wm_attribute (test.test_tkinter.test_misc.WmTest.test_wm_attribute) ... ok
test_wm_iconbitmap (test.test_tkinter.test_misc.WmTest.test_wm_iconbitmap) ... Timeout (0:10:00)!
Thread 0x00007ff85c48cc00 (most recent call first):
  File "/Users/runner/work/cpython/cpython/Lib/tkinter/__init__.py", line 2345 in wm_iconbitmap
  File "/Users/runner/work/cpython/cpython/Lib/test/test_tkinter/test_misc.py", line 582 in test_wm_iconbitmap
  File "/Users/runner/work/cpython/cpython/Lib/unittest/case.py", line 613 in _callTestMethod
  File "/Users/runner/work/cpython/cpython/Lib/unittest/case.py", line 667 in run
(...)

test.pythoninfo:

tkinter.TCL_VERSION: 9.0
tkinter.TK_VERSION: 9.0
tkinter.info_patchlevel: 9.0.3

The test_wm_iconbitmap() test was added by commit 58e9f95c4aa970db32a94b9152b51ede22f823bd.

Linked PRs

• gh-148032
• gh-153188
• gh-153189
• gh-153190
• gh-153191
• gh-153348
• gh-153450
• gh-153451
• gh-153452
• gh-153453

閱讀 Lib/test/test_tkinter/test_misc.py 中 WmTest.test_wm_iconbitmap 附近的內容，以及 Lib/tkinter/init.py:2345 中 traceback 的位置。使用 Tk 9.0.3 在 macOS / build and test (macos-26-intel) 上重現 timeout，然後審查連結的 PR；完成的標準是測試在 CI timeout 內完成。