Remove default .env from Kamal and just rely on .env.erb (Closes rails#51829)

Author: dhh

railties/lib/rails/generators/app_base.rb

@@ -731,6 +731,7 @@ def run_kamal
         bundle_command "binstubs kamal"
         bundle_command "exec kamal init"
 
+        remove_file ".env"
         template "env.erb", ".env.erb"
         template "config/deploy.yml", force: true
       end