Bump bundler from 1.7.5 to 2.1.4

lfdebrux · lfdebrux · commit 738c5cf4ed12 · 2022-03-07T15:03:57.000Z
Bumps bundler to the same version as used in the current ruby:2.75
Docker image (280416eb1a1c).
diff --git a/Gemfile.lock b/Gemfile.lock
@@ -105,4 +105,4 @@ RUBY VERSION
    ruby 2.7.5p203
 
 BUNDLED WITH
-   1.17.2
+   2.1.4
