Remove colorama

[davidism]

Tested echo, prompt, and other output utilities in a script, and styles seem to work fine. Tested in both Terminal and cmd.exe. I'm not clear when Windows 11 enabled ANSI by default, but realistically we can only support the latest version since that's the only version we and most people can get. An application that wants to support older Windows can still require colorama and call colorama.init() before main().

closes #2986

[kdeldycke]

Just added that branch to my matrix of tests in Click Extra: kdeldycke/click-extra@27f3999

Tl;Dr: No colorama regressions.

Results

The run is at https://github.com/kdeldycke/click-extra/actions/runs/26327147889

Fixed stack:

• Click branch iscolorama @ fd9d206
• Click Extra is 7.17.0.dev0 (3c0c0b9)
• Cloup is 3.0.9

OS	Python	Result
macos-26	3.10	✅ pass
macos-26	3.14	✅ pass
macos-26	3.14t	✅ pass
macos-26	3.15	✅ pass
macos-26-intel	3.10	✅ pass
macos-26-intel	3.14	✅ pass
macos-26-intel	3.14t	✅ pass
macos-26-intel	3.15	✅ pass
ubuntu-24.04-arm	3.10	✅ pass
ubuntu-24.04-arm	3.14	✅ pass
ubuntu-24.04-arm	3.14t	✅ pass
ubuntu-24.04-arm	3.15	✅ pass
ubuntu-slim	3.10	✅ pass
ubuntu-slim	3.14	✅ pass
ubuntu-slim	3.14t	✅ pass
ubuntu-slim	3.15	✅ pass
windows-11-arm	3.14	✅ pass
windows-11-arm	3.14t	✅ pass
windows-11-arm	3.15	✅ pass (but codecov upload failed)
windows-2025	3.10	✅ pass
windows-2025	3.14	✅ pass
windows-2025	3.14t	✅ pass
windows-2025	3.15	✅ pass

Some flaky runs had nothing to do with Colorama removal, just some CI/CD flaps from Click Extra project.

Note: windows-11-arm / py3.10 is omitted by design as no ARM64 Windows build exists for Python 3.10.

[kdeldycke]

Also see related documentation updates at: #3671