Remove row deduplication in incremental update

[joshua-spacetime]

The server deduplicates rows for incremental join updates before sending the updated rows to the client.

SpacetimeDB/crates/core/src/subscription/delta.rs

Lines 15 to 17 in 74661be

	/// Note, the 1.0 api does allow for duplicate rows.
	/// Hence this may be removed at any time after 1.0.
	pub fn eval_delta<'a, Tx: Datastore + DeltaStore>(

This is a bug.

It was necessary at the time it was introduced because the client SDKs did not handle duplicate rows. The SDKs were eventually updated to handle duplicate rows, but the deduplication on the server was never removed.

This has the potential to result in a corrupted SDK client cache for join subscriptions.

[joshua-spacetime]

While I don't know the exact query responsible, I believe this to be a manifestation of the bug.