Reverted performance related improvement to clusters-dbscan that broke builds

[smallsaucepan]

Reverted performance related improvement that was breaking builds. While faster, kdbush isn't released with a CJS variant and that caused dependency problems for users. Removes kdbush dependency and rolls back to using CJS compatible rbush 3.0.1.

Reverts #2885

Resolves #3018

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[mfedderly]

I think we should go ESM only for Turf 8 to simplify our own builds, so it would make sense to file a ticket to revert this in the 8 milestone. Consumers who are still using commonjs can use Node's --experimental-require-module if it isn't just enabled by default for them depending on version.