Bump activerecord from 3.2.14 to 6.1.7.1 in /pgcat/tests/ruby

Bumps [activerecord](https://github.com/rails/rails) from 3.2.14 to 6.1.7.1.
- [Release notes](https://github.com/rails/rails/releases)
- [Changelog](https://github.com/rails/rails/blob/v7.2.1/activerecord/CHANGELOG.md)
- [Commits](rails/rails@v3.2.14...v6.1.7.1)

---
updated-dependencies:
- dependency-name: activerecord
  dependency-type: direct:production
...

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

pgcat/tests/ruby/Gemfile.lock

@@ -1,12 +1,17 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    activerecord (3.2.14)
-    activesupport (7.0.7.1)
+    activemodel (6.1.7.1)
+      activesupport (= 6.1.7.1)
+    activerecord (6.1.7.1)
+      activemodel (= 6.1.7.1)
+      activesupport (= 6.1.7.1)
+    activesupport (6.1.7.1)
       concurrent-ruby (~> 1.0, >= 1.0.2)
       i18n (>= 1.6, < 2)
       minitest (>= 5.1)
       tzinfo (~> 2.0)
+      zeitwerk (~> 2.3)
     ast (2.4.2)
     concurrent-ruby (1.3.4)
     diff-lcs (1.5.0)
@@ -54,6 +59,7 @@ GEM
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
     unicode-display_width (2.1.0)
+    zeitwerk (2.6.17)
 
 PLATFORMS
   aarch64-linux