Backport PR #19766 on branch v3.4.x (Set colormap modification removal to 3.6.)#19767

tacaswell merged 1 commit intomatplotlib:v3.4.xmatplotlib/matplotlib:v3.4.xfrom

meeseeksmachine:auto-backport-of-pr-19766-on-v3.4.xmeeseeksmachine/matplotlib:auto-backport-of-pr-19766-on-v3.4.xCopy head branch name to clipboard