Escape secrets in inline command substitution

Kamal "inlines" calls to `kamal secrets` in the dotenv file, but the
results of the calls were not being escaped properly. To "fix" this
`kamal secrets fetch` escaped the JSON string before returning it.

The two errors cancelled out, but it meant that the commands didn't
work from a shell.

To fix, we'll escape the inline command results and remove the escaping
from `kamal secrets fetch`.

lib/kamal/cli/secrets.rb

@@ -7,7 +7,7 @@ class Kamal::Cli::Secrets < Kamal::Cli::Base
   def fetch(*secrets)
     results = adapter(options[:adapter]).fetch(secrets, **options.slice(:account, :from).symbolize_keys)
 
-    return_or_puts JSON.dump(results).shellescape, inline: options[:inline]
+    return_or_puts JSON.dump(results), inline: options[:inline]
   end
 
   desc "extract", "Extract a single secret from the results of a fetch call"

lib/kamal/secrets/dotenv/inline_command_substitution.rb

@@ -16,7 +16,7 @@ class Kamal::Secrets::Dotenv::InlineCommandSubstitution
         else
           if command =~ /\A\s*kamal\s*secrets\s+/
             # Inline the command
-            inline_secrets_command(command)
+            inline_secrets_command(command).shellescape
           else
             # Execute the command and return the value
             `#{command}`.chomp