Bump puma from 5.6.7 to 5.6.8

Bumps [puma](https://github.com/puma/puma) from 5.6.7 to 5.6.8.
- [Release notes](https://github.com/puma/puma/releases)
- [Changelog](https://github.com/puma/puma/blob/master/History.md)
- [Commits](https://github.com/puma/puma/compare/v5.6.7...v5.6.8)

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

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

Gemfile.lock

@@ -367,7 +367,7 @@ GEM
     net-smtp (0.4.0)
       net-protocol
     net-ssh (7.2.0)
-    nio4r (2.6.0)
+    nio4r (2.7.0)
     nokogiri (1.16.2)
       mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
@@ -444,7 +444,7 @@ GEM
       pronto (~> 0.11.0)
       scss_lint (~> 0.43, >= 0.43.0)
     public_suffix (4.0.7)
-    puma (5.6.7)
+    puma (5.6.8)
       nio4r (~> 2.0)
     racc (1.7.3)
     rack (2.2.8)
@@ -755,7 +755,7 @@ DEPENDENCIES
   pronto-eslint (~> 0.11.1)
   pronto-rubocop (~> 0.11.5)
   pronto-scss (~> 0.11.0)
-  puma (~> 5.6.7)
+  puma (~> 5.6.8)
   rails (= 6.1.7.6)
   rails-assets-markdown-it (~> 9.0.1)!
   recipient_interceptor (~> 0.3.1)