Bump puma from 5.6.4 to 5.6.7 in /server

Bumps [puma](https://github.com/puma/puma) from 5.6.4 to 5.6.7.
- [Release notes](https://github.com/puma/puma/releases)
- [Changelog](https://github.com/puma/puma/blob/master/History.md)
- [Commits](puma/puma@v5.6.4...v5.6.7)

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

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

server/Gemfile

@@ -8,7 +8,7 @@ gem 'rails', '~> 6.1', '>= 6.1.3.1'
 # Use postgresql as the database for Active Record
 gem 'pg', '~> 1.1'
 # Use Puma as the app server
-gem 'puma', '5.6.4'
+gem 'puma', '5.6.7'
 # Use SCSS for stylesheets
 gem 'sass-rails', '>= 6'
 # Transpile app-like JavaScript. Read more: https://github.com/rails/webpacker

server/Gemfile.lock

@@ -288,7 +288,7 @@ GEM
     pry-rails (0.3.9)
       pry (>= 0.10.4)
     public_suffix (5.0.1)
-    puma (5.6.4)
+    puma (5.6.7)
       nio4r (~> 2.0)
     raabro (1.4.0)
     racc (1.7.1)
@@ -495,7 +495,7 @@ DEPENDENCIES
   pg (~> 1.1)
   pry
   pry-rails
-  puma (= 5.6.4)
+  puma (= 5.6.7)
   rack-cors (~> 1.1.1)
   rack-mini-profiler (~> 2.0)
   rails (~> 6.1, >= 6.1.3.1)