Recommendation is to avoid using the year nomenclature as this
information is already encoded in the git repo. Avoids needing to
repeatly update.
Also updates AUTHORS.txt from current repo with contributor names
Reduce each (Accel & Fallback) to 3 options: Off, Fast, Good. Fast AA
in accelerated canvas uses SMAA with tweaks suggested by David Beinder.
Good AA is super-sampled x2.
Cairo is similarly reduced to Off, Fast, Good, which map to the Cairo
options themselves. Best is removed as it mostly affects text rendering
and not line drawing (as our text is)
Fixes https://gitlab.com/kicad/code/kicad/-/issues/8522
Conservative makes SMAA usable in Eeschema through weaker AA.
Aggressive reduces some artifacts compared to the High preset.
Restores the unused Ultra preset in the shader source to its original state.