Bump version in main to 8.10.3

[JoshMock]

Version bump automation is currently broken for this repo. Bumping manually.

[github-actions]

The backport to 8.10 failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-8.10 8.10
# Navigate to the new working tree
cd .worktrees/backport-8.10
# Create a new branch
git switch --create backport-2066-to-8.10
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 abd5018cfe550ee3d8e10753bdb5696e52e9fb36
# Push it to GitHub
git push --set-upstream origin backport-2066-to-8.10
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-8.10

Then, create a pull request where the base branch is 8.10 and the compare/head branch is backport-2066-to-8.10.