[Security] Bump puma from 4.3.5 to 4.3.8

Bumps [puma](https://github.com/puma/puma) from 4.3.5 to 4.3.8. **This update includes a security fix.**
- [Release notes](https://github.com/puma/puma/releases)
- [Changelog](https://github.com/puma/puma/blob/master/History.md)
- [Commits](puma/puma@v4.3.5...v4.3.8)

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

Gemfile.lock

@@ -157,7 +157,9 @@ GEM
     marcel (0.3.3)
       mimemagic (~> 0.3.2)
     method_source (1.0.0)
-    mimemagic (0.3.5)
+    mimemagic (0.3.10)
+      nokogiri (~> 1)
+      rake
     mina (1.2.3)
       open4 (~> 1.3.4)
       rake
@@ -177,7 +179,7 @@ GEM
       ruby2_keywords (~> 0.0.1)
     nenv (0.3.0)
     newrelic_rpm (6.11.0.365)
-    nio4r (2.5.2)
+    nio4r (2.5.7)
     nokogiri (1.11.2)
       mini_portile2 (~> 2.5.0)
       racc (~> 1.4)
@@ -196,7 +198,7 @@ GEM
       coderay (~> 1.1)
       method_source (~> 1.0)
     public_suffix (4.0.3)
-    puma (4.3.5)
+    puma (4.3.8)
       nio4r (~> 2.0)
     racc (1.5.2)
     rack (2.2.3)