fix stroke ppu for WGLMakie

[SimonDanisch]

@ffreyer should have tested your pr before merging :D

[MakieBot]

Compile Times benchmark

Note, that these numbers may fluctuate on the CI servers, so take them with a grain of salt. All benchmark results are based on the mean time and negative percent mean faster than the base branch. Note, that GLMakie + WGLMakie run on an emulated GPU, so the runtime benchmark is much slower. Results are from running:

using_time = @ctime using Backend
# Compile time
create_time = @ctime fig = scatter(1:4; color=1:4, colormap=:turbo, markersize=20, visible=true)
display_time = @ctime Makie.colorbuffer(display(fig))
# Runtime
create_time = @benchmark fig = scatter(1:4; color=1:4, colormap=:turbo, markersize=20, visible=true)
display_time = @benchmark Makie.colorbuffer(fig)

	using	create	display	create	display
GLMakie	3.46s (3.41, 3.49) 0.03+-	387.02ms (380.74, 395.78) 6.28+-	475.84ms (464.71, 513.20) 16.80+-	7.33ms (7.26, 7.46) 0.07+-	25.48ms (25.37, 25.61) 0.09+-
master	3.45s (3.43, 3.48) 0.02+-	392.86ms (383.00, 410.21) 10.17+-	469.12ms (465.46, 472.58) 2.42+-	7.26ms (7.10, 7.41) 0.09+-	25.50ms (25.42, 25.62) 0.07+-
evaluation	1.00x invariant, 0.01s (0.39d, 0.49p, 0.02std)	1.02x invariant, -5.84ms (-0.69d, 0.23p, 8.23std)	0.99x invariant, 6.72ms (0.56d, 0.33p, 9.61std)	0.99x invariant, 0.07ms (0.84d, 0.14p, 0.08std)	1.00x invariant, -0.02ms (-0.24d, 0.66p, 0.08std)
CairoMakie	3.14s (3.07, 3.20) 0.04+-	332.15ms (321.07, 356.14) 12.50+-	144.96ms (140.22, 157.78) 6.01+-	7.48ms (7.32, 7.71) 0.15+-	606.44μs (600.93, 610.52) 3.87+-
master	3.11s (3.06, 3.16) 0.03+-	328.26ms (316.07, 354.83) 13.36+-	143.84ms (139.56, 152.17) 4.91+-	7.50ms (7.31, 7.79) 0.16+-	605.21μs (600.53, 612.41) 3.74+-
evaluation	0.99x invariant, 0.03s (0.75d, 0.19p, 0.04std)	0.99x invariant, 3.9ms (0.30d, 0.58p, 12.93std)	0.99x invariant, 1.13ms (0.21d, 0.71p, 5.46std)	1.00x invariant, -0.02ms (-0.15d, 0.78p, 0.15std)	1.00x invariant, 1.23μs (0.32d, 0.56p, 3.81std)
WGLMakie	3.84s (3.77, 3.93) 0.06+-	504.81ms (328.49, 588.63) 114.41+-	9.46s (9.25, 9.71) 0.17+-	9.72ms (9.56, 9.94) 0.15+-	73.47ms (69.76, 79.64) 4.01+-
master	3.87s (3.84, 3.94) 0.04+-	342.19ms (336.54, 351.86) 5.52+-	9.48s (9.33, 9.62) 0.11+-	9.88ms (9.54, 11.04) 0.53+-	75.48ms (69.06, 82.22) 5.77+-
evaluation	1.01x invariant, -0.03s (-0.57d, 0.31p, 0.05std)	0.68x slower❌, 162.62ms (2.01d, 0.01p, 59.97std)	1.00x invariant, -0.02s (-0.14d, 0.80p, 0.14std)	1.02x invariant, -0.16ms (-0.42d, 0.46p, 0.34std)	1.03x invariant, -2.01ms (-0.40d, 0.47p, 4.89std)