Bump pg from 1.5.6 to 1.5.8

Bumps [pg](https://github.com/ged/ruby-pg) from 1.5.6 to 1.5.8.
- [Changelog](https://github.com/ged/ruby-pg/blob/master/History.md)
- [Commits](https://github.com/ged/ruby-pg/compare/v1.5.6...v1.5.8)

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

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

Gemfile.lock

@@ -427,7 +427,7 @@ GEM
       hashery (~> 2.0)
       ruby-rc4
       ttfunk
-    pg (1.5.6)
+    pg (1.5.8)
     pg_search (2.3.7)
       activerecord (>= 6.1)
       activesupport (>= 6.1)
@@ -754,7 +754,7 @@ DEPENDENCIES
   omniauth-twitter (~> 1.4.0)
   paranoia (~> 2.6.3)
   pdf-reader (~> 2.12.0)
-  pg (~> 1.5.6)
+  pg (~> 1.5.8)
   pg_search (~> 2.3.7)
   pronto (~> 0.11.2)
   pronto-erb_lint (~> 0.1.6)