Bump pg from 1.4.6 to 1.5.1

Bumps [pg](https://github.com/ged/ruby-pg) from 1.4.6 to 1.5.1.
- [Release notes](https://github.com/ged/ruby-pg/releases)
- [Changelog](https://github.com/ged/ruby-pg/blob/master/History.md)
- [Commits](https://github.com/ged/ruby-pg/compare/v1.4.6...v1.5.1)

---
updated-dependencies:
- dependency-name: pg
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile.lock

@@ -273,7 +273,7 @@ GEM
     parallel (1.23.0)
     parser (3.2.2.0)
       ast (~> 2.4.1)
-    pg (1.4.6)
+    pg (1.5.1)
     prometheus_exporter (2.0.8)
       webrick
     pry (0.14.2)