Add a MixAssign trait and remove the Float requirement from Mix

[Ogeon]

This adds a MixAssign trait that allows interpolating without moving or cloning more than necessary. I have also removed the requirement that the Scalar implements Float.

Breaking Change

Removing the Float requirement also removes the implication T: Mix -> T::Scalar: Float, possibly breaking some generic implementations (hence the changes in gradinet).

[github-actions]

Benchmark for a63abcb

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Test	PR Benchmark	Master Benchmark	%
Cie family/lab to lch	3.5±0.16µs	3.3±0.23µs	+6.06%
Cie family/lab to xyz	990.3±55.87ns	951.2±24.88ns	+4.11%
Cie family/lch to lab	2.6±0.18µs	2.4±0.10µs	+8.33%
Cie family/linsrgb to xyz	3.8±0.08µs	3.7±0.25µs	+2.70%
Cie family/xyz to lab	11.1±0.82µs	10.9±0.56µs	+1.83%
Cie family/xyz to yxy	727.3±14.42ns	759.5±44.51ns	-4.24%
Cie family/yxy to xyz	614.7±11.88ns	640.7±75.01ns	-4.06%
Matrix functions/matrix_inverse	13.2±1.03ns	13.2±0.52ns	0.00%
Matrix functions/multiply_3x3	11.5±1.01ns	10.8±0.71ns	+6.48%
Matrix functions/multiply_rgb_to_xyz	4.9±0.21ns	4.8±0.28ns	+2.08%
Matrix functions/multiply_xyz	4.8±0.25ns	4.9±0.29ns	-2.04%
Matrix functions/multiply_xyz_to_rgb	5.0±0.41ns	4.9±0.44ns	+2.04%
Matrix functions/rgb_to_xyz_matrix	25.0±1.65ns	25.2±0.56ns	-0.79%
Rgb family/hsl to hsv	808.0±48.42ns	808.8±40.79ns	-0.10%
Rgb family/hsl to linear hsl	9.8±0.72µs	9.6±0.23µs	+2.08%
Rgb family/hsl to rgb	2.4±0.08µs	2.5±0.26µs	-4.00%
Rgb family/hsv to hsl	1176.8±99.37ns	1196.8±79.03ns	-1.67%
Rgb family/hsv to hwb	250.3±11.12ns	267.8±23.77ns	-6.53%
Rgb family/hsv to linear hsv	8.8±0.39µs	8.6±0.57µs	+2.33%
Rgb family/hsv to rgb	2.5±0.16µs	2.4±0.16µs	+4.17%
Rgb family/hwb to hsv	568.4±29.48ns	548.5±21.71ns	+3.63%
Rgb family/hwb to linear hwb	10.8±0.95µs	10.6±0.31µs	+1.89%
Rgb family/linear hsl to hsl	10.2±0.87µs	9.8±0.39µs	+4.08%
Rgb family/linear hsv to hsv	9.0±0.41µs	9.6±0.32µs	-6.25%
Rgb family/linear hwb to hwb	11.6±0.70µs	11.3±0.36µs	+2.65%
Rgb family/linsrgb to rgb	4.6±0.20µs	4.8±0.34µs	-4.17%
Rgb family/linsrgb_f32 to rgb_u8	6.3±0.18µs	6.6±0.77µs	-4.55%
Rgb family/rgb to hsl	876.0±71.41ns	857.0±50.19ns	+2.22%
Rgb family/rgb to hsv	745.7±139.04ns	691.9±42.21ns	+7.78%
Rgb family/rgb to linsrgb	5.0±0.35µs	5.0±0.44µs	0.00%
Rgb family/rgb_u8 to linsrgb_f32	5.3±0.17µs	5.4±0.33µs	-1.85%
Rgb family/xyz to linsrgb	8.5±0.38µs	9.1±0.49µs	-6.59%

[Ogeon]

bors r+

[bors]

Build succeeded:

• ci