Fixed libXau error in wheels for macOS 10.10

[radarhere]

#6862 (comment) is a report from a user that Pillow 10.2.0 wheels cause the following error on macOS 10.10

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/Users/just/code/git/drawbot/venv312/lib/python3.12/site-packages/PIL/Image.py", line 84, in <module>
    from . import _imaging as core
ImportError: dlopen(/Users/just/code/git/drawbot/venv312/lib/python3.12/site-packages/PIL/_imaging.cpython-312-darwin.so, 2): Library not loaded: @loader_path/libXau.6.0.0.dylib
  Referenced from: /Users/just/code/git/drawbot/venv312/lib/python3.12/site-packages/PIL/.dylibs/libxcb.1.1.0.dylib
  Reason: no suitable image found.  Did find:
	/Users/just/code/git/drawbot/venv312/lib/python3.12/site-packages/PIL/.dylibs/libXau.6.0.0.dylib: cannot load 'libXau.6.0.0.dylib' (load command 0x80000034 is unknown)
	/Users/just/code/git/drawbot/venv312/lib/python3.12/site-packages/PIL/.dylibs/libXau.6.0.0.dylib: cannot load 'libXau.6.0.0.dylib' (load command 0x80000034 is unknown)

Investigating, I found that when generating wheels, GitHub Actions is outputting

ld: warning: dylib (/usr/local/Cellar/libxau/1.0.11/lib/libXau.dylib) was built for newer macOS version (12.0) than being linked (10.10)

This PR uninstalls brew's libxau, and starts building libxcb's dependencies on macOS x86-64 instead.

The user has confirmed that the wheels with these changes work on macOS 10.10.

[hugovk]

Thanks!

I'll note this adds an extra 10 minutes to the macOS x86_64 wheel job (36->46min) and macOS OS X 10.10 has been EOL for 6.5 years:

cycle	codename	release	latest	latest release	eol	link
14	Sonoma	2023-09-26	14.3	2024-01-22	False	https://support.apple.com/HT213895
13	Ventura	2022-10-24	13.6.4	2024-01-22	False	https://support.apple.com/HT213268
12	Monterey	2021-10-25	12.7.3	2024-01-22	False	https://support.apple.com/HT212585
11	Big Sur	2020-11-12	11.7.10	2023-09-11	2023-09-26	https://support.apple.com/HT211896
10.15	Catalina	2019-10-07	10.15.7	2020-09-24	2022-09-12	https://support.apple.com/HT210642
10.14	Mojave	2018-09-24	10.14.6	2019-07-22	2021-10-25
10.13	High Sierra	2017-09-25	10.13.6	2018-07-09	2020-12-01
10.12	Sierra	2016-09-20	10.12.6	2017-07-19	2019-10-01
10.11	El Capitan	2015-09-30	10.11.6	2016-07-18	2018-12-01
10.10	Yosemite	2014-10-16	10.10.5	2015-08-13	2017-08-01
10.9	Mavericks	2013-10-22	10.9.5	2014-09-17	2016-12-01

But the wheel builds are already very slow (1d 10h 21m total CPU time!) so another 10 minutes hardly makes a difference. And we may drop unofficial support for EOL OS versions in future releases with no notice.