CI(g.list): migrate tests to pytest

[Khansa435]

Description

This PR migrates the legacy GMlistWrongParamertersTest from the grass.gunittest framework to the modern pytest framework for the g.list module.

Key Changes:

• Migrated parameter validation tests (mutually exclusive flags) to general/g.list/tests/g_list_test.py.
• Used pytest.mark.parametrize for clean, data-driven test cases.
• Implemented explicit error verification using pytest.raises(CalledModuleError).
• Added a new test case for invalid format and flags combinations.
• Cleaned up syntax and ensured compatibility with the existing simple_dataset fixture.

Related Issue

Fixes #7226

Automated Tests

• Verified using a local standalone script that replicates the CalledModuleError catching on Windows (OSGeo4W).
• The migrated code follows the pattern of existing tests in the g.list suite to ensure CI compatibility.

Manual Verification

• Verified that the g.list module correctly identifies and reports mutually exclusive flags (-p, -t, -f, etc.) within the new test structure.

[wenzeslaus]

This is generated without AI or human looking at any existing tests. Also, migrate would generally mean remove the old stuff.