Backport PR #29721 on branch v3.10.x (FIX: pyplot auto-backend detection case-sensitivity fixup)#29754

dstansby merged 1 commit intomatplotlib:v3.10.xmatplotlib/matplotlib:v3.10.xfrom

meeseeksmachine:auto-backport-of-pr-29721-on-v3.10.xmeeseeksmachine/matplotlib:auto-backport-of-pr-29721-on-v3.10.xCopy head branch name to clipboard