Bump amphp/postgres from 2.0.0 to 2.1.0 in /by-language/php-amphp

Bumps [amphp/postgres](https://github.com/amphp/postgres) from 2.0.0 to 2.1.0.
- [Release notes](https://github.com/amphp/postgres/releases)
- [Commits](amphp/postgres@v2.0.0...v2.1.0)

---
updated-dependencies:
- dependency-name: amphp/postgres
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>