databases/pgvector: Update from 0.7.2 to 0.7.3
Changelog: * Fixed failed to add index item error with sparsevec * Fixed compilation error with FreeBSD ARM * Fixed compilation warning with MSVC and Postgres 16 Taken from: https://github.com/pgvector/pgvector/blob/master/CHANGELOG.md
MFH: 2024Q3
(cherry picked from commit 0d6d385a0223ac61bb584321d55b58339be37ac4)