This reverts commit a915df1.

The special macOS dark cursor is still useful for users stuck on older
versions of macOS. Even on macOS Catalina, this cursor is helpful for
reducing visual bloat.

This reduces code duplication and makes it significantly easier to make
changes to the text cursor without having to individually modify several
files.

Now that there's a common mouse-text class for text cursors, we can
apply the special macOS dark cursor to many elements at once to improve
consistency.

Since the cursor is now applied to all relevant elements, this fixes
#94144 without needing to revert the cursor entirely.