Bump puma from 5.3.2 to 6.3.1 in /geode-book

Bumps [puma](https://github.com/puma/puma) from 5.3.2 to 6.3.1.
- [Release notes](https://github.com/puma/puma/releases)
- [Changelog](https://github.com/puma/puma/blob/master/History.md)
- [Commits](puma/puma@v5.3.2...v6.3.1)

---
updated-dependencies:
- dependency-name: puma
  dependency-type: indirect
...

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

geode-book/Gemfile.lock

@@ -168,7 +168,7 @@ GEM
     minitest (5.14.4)
     multi_json (1.15.0)
     multipart-post (2.1.1)
-    nio4r (2.5.7)
+    nio4r (2.5.9)
     nokogiri (1.10.1)
       mini_portile2 (~> 2.4.0)
     padrino-helpers (0.13.3.4)
@@ -179,7 +179,7 @@ GEM
       activesupport (>= 3.1)
     parallel (1.20.1)
     public_suffix (4.0.6)
-    puma (5.3.2)
+    puma (6.3.1)
       nio4r (~> 2.0)
     rack (1.6.13)
     rack-livereload (0.3.17)