simplify `colorsys.rgb_to_hsv`

Feature or enhancement

Proposal:

By inlining some variables, the number of operations performed can be reduced. Example:
with

gc = (maxc-g) / rangec
bc = (maxc-b) / rangec

then

h = bc-gc
h = (maxc-b)/rangec - (maxc-g)/rangec
h = ((maxc-b) - (maxc-g)) / rangec
h = (maxc - b - maxc + g) / rangec
h = (g-b) / rangec

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

Linked PRs

• gh-124880

从 colorsys.rgb_to_hsv 入口点开始，并在进行更改前审查链接的 PR gh-124880。当等效计算使用更少的中间操作，同时保持函数行为不变时，工作即完成。