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](puma/puma@v5.6.7...v5.6.8)

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

Signed-off-by: dependabot[bot] <[email protected]>

Gemfile.lock

@@ -105,10 +105,12 @@ GEM
       timeout
     net-smtp (0.3.3)
       net-protocol
-    nio4r (2.5.9)
+    nio4r (2.7.0)
     nokogiri (1.15.4-arm64-darwin)
       racc (~> 1.4)
-    puma (5.6.7)
+    nokogiri (1.15.4-x86_64-linux)
+      racc (~> 1.4)
+    puma (5.6.8)
       nio4r (~> 2.0)
     racc (1.7.1)
     rack (2.2.8)
@@ -182,6 +184,7 @@ GEM
 
 PLATFORMS
   arm64-darwin-20
+  x86_64-linux
 
 DEPENDENCIES
   adminlte-rails