DEV: Bump pg from 1.2.1 to 1.2.2 (#8685)

Bumps [pg](https://github.com/ged/ruby-pg) from 1.2.1 to 1.2.2.
- [Release notes](https://github.com/ged/ruby-pg/releases)
- [Changelog](https://github.com/ged/ruby-pg/blob/master/History.rdoc)
- [Commits](https://github.com/ged/ruby-pg/compare/v1.2.1...v1.2.2)

Very safe upgrade, Discourse is not impacted by any of the changes.

Gemfile.lock

@@ -258,7 +258,7 @@ GEM
       parallel
     parser (2.7.0.2)
       ast (~> 2.4.0)
-    pg (1.2.1)
+    pg (1.2.2)
     progress (3.5.2)
     pry (0.12.2)
       coderay (~> 1.1.0)