Migrate from pgvecto.rs to VectorChord

[ngosang]

It's the successor of pgvecto.rs, developed by the same team.
VectorChord 0.1.0 was released => https://github.com/tensorchord/VectorChord/releases/tag/0.1.0
There is a blog post with impressive benchmarks => https://blog.pgvecto.rs/vectorchord-store-400k-vectors-for-1-in-postgresql

Related => #14280

[danieldietzler]

That is already our plan, yep :)

[martabal]

More context: tensorchord/VectorChord#101