Bump puma from 6.4.2 to 6.4.3 in /webapp/ruby

Bumps [puma](https://github.com/puma/puma) from 6.4.2 to 6.4.3.
- [Release notes](https://github.com/puma/puma/releases)
- [Changelog](https://github.com/puma/puma/blob/master/History.md)
- [Commits](puma/puma@v6.4.2...v6.4.3)

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

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

webapp/ruby/Gemfile.lock

@@ -9,8 +9,8 @@ GEM
     mysql2 (0.5.6)
     mysql2-cs-bind (0.1.1)
       mysql2
-    nio4r (2.7.0)
-    puma (6.4.2)
+    nio4r (2.7.3)
+    puma (6.4.3)
       nio4r (~> 2.0)
     rack (3.0.9.1)
     rack-protection (4.0.0)