Auto merge of #3982 - pietroalbini:pg13, r=Turbo87
Auto merge of #3982 - pietroalbini:pg13, r=Turbo87

Bump CI to PostgreSQL 13

This PR bumps CI's PostgreSQL to version 13, to match what we will upgrade to tomorrow.

rust-lang/crates.io,rust-lang/crates.io,rust-lang/crates.io,rust-lang/crates.io