Fix division by zero bug in colorsys.rgb_to_hls() for near-white colors

[Anuj092]

Fixes gh-106498: Prevent ZeroDivisionError when converting RGB values very close to white (e.g., (0.9999999999999999, 1, 1)) to HLS.

Changes:

• Add numerical stability check in rgb_to_hls() function
• When denominator (2.0 - maxc - minc) is very close to zero, set s = 0.0
• Improve HSV hue handling with explicit normalization
• Add test case for hue wrapping edge cases

This fix prevents crashes when converting colors very close to pure white while maintaining backward compatibility and mathematical correctness.

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[ZeroIntensity]

Hi @Anuj092!

We appreciate your enthusiasm, but using AI to generate pull requests is not helpful. LLMs can be useful for many things, but in this case, it's just noise on our issue tracker (see our AI policy). The underlying bug that this PR is fixing has already been fixed since Python 3.10.

If you're interested in contributing, you're free to use AI, but please be sure to use your own critical thinking before submitting a pull request. Thanks!