chore(deps): 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] <support@github.com>

Gemfile.lock

@@ -29,7 +29,7 @@ GEM
     method_source (1.0.0)
     mini_mime (1.0.2)
     minitest (5.19.0)
-    nio4r (2.5.9)
+    nio4r (2.7.0)
     oj (3.10.6)
     parallel (1.19.2)
     parser (2.7.1.4)
@@ -41,7 +41,7 @@ GEM
     pry-byebug (3.9.0)
       byebug (~> 11.0)
       pry (~> 0.13.0)
-    puma (5.6.7)
+    puma (5.6.8)
       nio4r (~> 2.0)
     rack (2.2.6.4)
     rack-test (1.1.0)