Ensure uv pip freeze is colorless

[Stealthii]

The 'uv pip freeze' command should automatically determine whether or not to provide coloring if the output is going to a terminal or TTY with support. This is not happening in this case.

Ensuring color is always disabled for this command is a good first step to work around this issue. Fixes #38.

[Stealthii]

Before:

$ file .tox/py38-mindeps/constraints.txt
.tox/py38-mindeps/constraints.txt: ASCII text, with escape sequences

After:

$ file .tox/py38-mindeps/constraints.txt
.tox/py38-mindeps/constraints.txt: ASCII text

[gaborbernat]

Tests please.

[Stealthii]

Apologies, been struggling with testing this one.

• Similar tests in tox test_python_api.py (256-279) only test against result.out, which is already sanitised. pip is also in our instance, not installed
• Setting up demo_pkg_inline, even running a full install during the test, I'm stumped for a mechanism to test against the stdout of a call. I can't find any tests that do this in tox, and the two IOWrappers at call[0][2] are empty (I'd considered them potentially stdout/stderr)

[gaborbernat]

Just assert against assert execute_calls.call_args ?

[Stealthii]

Ah ok - I was trying to write a test for the actual output from installed() to validate it as pure string. I've added a test for the call arguments themselves in fab11cf.

[gaborbernat]