fix(circleci): install file command

Was used in paperclip validations, and due to the following bug it is missing from ruby 3.1 image: CircleCI-Public/cimg-ruby#106

Author: difernandez

.circleci/config.yml

@@ -38,6 +38,7 @@ commands:
             cd spec/dummy/
             xargs -a Aptfile sudo apt-get install
             sudo apt-get install libvips
+            sudo apt-get install file
       - run:
           name: Install bundle dependencies
           command: |