Bump puma from 5.6.8 to 5.6.9 in the bundler group

Bumps the bundler group with 1 update: [puma](https://github.com/puma/puma).


Updates `puma` from 5.6.8 to 5.6.9
- [Release notes](https://github.com/puma/puma/releases)
- [Changelog](https://github.com/puma/puma/blob/master/History.md)
- [Commits](puma/puma@v5.6.8...v5.6.9)

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

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

Gemfile

@@ -8,7 +8,7 @@ gem "rails", "~> 6.1"
 # Use sqlite3 as the database for Active Record
 gem "sqlite3", "~> 1.4"
 # Use Puma as the app server
-gem "puma", "~> 5.0"
+gem "puma", "~> 5.6"
 # Use SCSS for stylesheets
 gem "sass-rails", "~> 5"
 # https://github.com/rails/jsbundling-rails

Gemfile.lock

@@ -175,7 +175,7 @@ GEM
     prometheus-client (4.2.3)
       base64
     public_suffix (6.0.1)
-    puma (5.6.8)
+    puma (5.6.9)
       nio4r (~> 2.0)
     raabro (1.4.0)
     racc (1.8.1)
@@ -357,7 +357,7 @@ DEPENDENCIES
   mocha
   net-pop!
   prometheus-client
-  puma (~> 5.0)
+  puma (~> 5.6)
   rack-mini-profiler (~> 2.0)
   rails (~> 6.1)
   rufus-scheduler