Fix spelling of exclusiveKeys

[sypets]

This property was sometimes spelled as all-lowercase.

[github-actions]

The backport to 11.5 failed:

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

stderr

error: could not apply f836b18... Fix spelling of exclusiveKeys
hint: After resolving the conflicts, mark them with
hint: "git add/rm <pathspec>", then run
hint: "git cherry-pick --continue".
hint: You can instead skip this commit with "git cherry-pick --skip".
hint: To abort and get back to the state before "git cherry-pick",
hint: run "git cherry-pick --abort".

stdout

Auto-merging Documentation/ColumnsConfig/Type/Select/CheckBox/Properties.rst
CONFLICT (content): Merge conflict in Documentation/ColumnsConfig/Type/Select/CheckBox/Properties.rst
Auto-merging Documentation/ColumnsConfig/Type/Select/MultipleSideBySide/Properties.rst
CONFLICT (content): Merge conflict in Documentation/ColumnsConfig/Type/Select/MultipleSideBySide/Properties.rst
Auto-merging Documentation/ColumnsConfig/Type/Select/Single/Properties.rst
CONFLICT (content): Merge conflict in Documentation/ColumnsConfig/Type/Select/Single/Properties.rst
Auto-merging Documentation/ColumnsConfig/Type/Select/SingleBox/Properties.rst
CONFLICT (content): Merge conflict in Documentation/ColumnsConfig/Type/Select/SingleBox/Properties.rst
Auto-merging Documentation/ColumnsConfig/Type/Select/Tree/Properties.rst
CONFLICT (content): Merge conflict in Documentation/ColumnsConfig/Type/Select/Tree/Properties.rst

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-11.5 11.5
# Navigate to the new working tree
cd .worktrees/backport-11.5
# Create a new branch
git switch --create backport-857-to-11.5
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick f836b18add58044abcf097e6457a7e7e7f5cfeea
# Push it to GitHub
git push --set-upstream origin backport-857-to-11.5
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-11.5

Then, create a pull request where the base branch is 11.5 and the compare/head branch is backport-857-to-11.5.