Bump puma from 5.6.8 to 6.5.0 in /backend

Bumps [puma](https://github.com/puma/puma) from 5.6.8 to 6.5.0.
- [Release notes](https://github.com/puma/puma/releases)
- [Changelog](https://github.com/puma/puma/blob/master/History.md)
- [Commits](puma/puma@v5.6.8...v6.5.0)

---
updated-dependencies:
- dependency-name: puma
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

backend/Gemfile

@@ -18,7 +18,7 @@ gem "mongoid", "8.1.3" # https://www.mongodb.com/docs/mongoid/current/reference/
 gem "pg"
 
 # Use Puma as the app server
-gem "puma", "5.6.8"
+gem "puma", "6.5.0"
 
 # Authentication libraries
 gem "cancancan", "~> 3.5.0"

backend/Gemfile.lock

@@ -285,7 +285,7 @@ GEM
       timeout
     net-smtp (0.5.0)
       net-protocol
-    nio4r (2.7.3)
+    nio4r (2.7.4)
     nokogiri (1.16.6)
       mini_portile2 (~> 2.8.2)
       racc (~> 1.4)
@@ -323,7 +323,7 @@ GEM
     psych (5.1.2)
       stringio
     public_suffix (5.0.4)
-    puma (5.6.8)
+    puma (6.5.0)
       nio4r (~> 2.0)
     pusher (2.0.3)
       httpclient (~> 2.8)
@@ -534,7 +534,7 @@ DEPENDENCIES
   pry-byebug
   pry-doc
   pry-rails
-  puma (= 5.6.8)
+  puma (= 6.5.0)
   pusher
   rack-cors (= 2.0.1)
   rack-timeout