Bug report

Bug description:

The recent builds on the 3.13 and 3.12 branches are failing for macos-13 (and 3.11 and earlier likely will as well):

• https://github.com/python/cpython/actions/workflows/build.yml?query=branch%3A3.13
• https://github.com/python/cpython/actions/workflows/build.yml?query=branch%3A3.12

For example https://github.com/python/cpython/actions/runs/12052665181/job/33606528979#step:9:1072 :

2 tests failed:
    test_tkinter test_ttk

This is because we install unpinned Tcl/Tk from Homebrew which has recently upgraded from 8.6 to 9.0:

main isn't failing because it's also recently been updated to prepare for 9.0.

For now, let's pin main and earlier branches to 8.6 and start testing 9.0 later (or on a buildbot):

https://formulae.brew.sh/formula/tcl-tk@8

CPython versions tested on:

3.12, 3.13, 3.14

Operating systems tested on:

macOS

Linked PRs

• gh-127359: Pin Tcl/Tk to 8 (8.6) for testing macOS #127365
• [3.13] gh-127359: Pin Tcl/Tk to 8 (8.6) for testing macOS (#127365) #127393
• [3.12] gh-127359: Pin Tcl/Tk to 8 (8.6) for testing macOS (GH-127365) #127394
• [3.11] gh-127359: Pin Tcl/Tk to 8 (8.6) for testing macOS (GH-127365) #127407
• [3.10] gh-127359: Pin Tcl/Tk to 8 (8.6) for testing macOS (GH-127365) #127408
• [3.9] gh-127359: Pin Tcl/Tk to 8 (8.6) for testing macOS (GH-127365) #127409