dep: explicitly add bundler-audit

Gemfile

@@ -48,6 +48,7 @@ gem "thruster"
 group :development, :test do
   gem "debug"
   gem "rubocop-rails-omakase", require: false
+  gem "bundler-audit", require: false
   gem "faker", require: false
   gem "brakeman", require: false
 end

Gemfile.lock

@@ -140,6 +140,9 @@ GEM
     brakeman (8.0.4)
       racc
     builder (3.3.0)
+    bundler-audit (0.9.3)
+      bundler (>= 1.2.0)
+      thor (~> 1.0)
     capybara (3.40.0)
       addressable
       matrix
@@ -412,6 +415,7 @@ DEPENDENCIES
   bcrypt
   benchmark
   brakeman
+  bundler-audit
   capybara
   debug
   faker
@@ -444,4 +448,4 @@ DEPENDENCIES
   webmock
 
 BUNDLED WITH
-   4.0.13
+  4.0.13