refactor: remove deprecated YAML template files

- Deleted all 'template.yml' files from various blueprints as part of the transition to TOML format.
- Updated the script to delete the 'template.yml' files instead of converting them to 'template.toml'.

blueprints/mailpit/template.yml

@@ -1,15 +0,0 @@
-variables:
-  main_domain: ${domain}
-  default_password: ${password}
-
-config:
-  domains:
-    - serviceName: mailpit
-      port: 8025
-      host: ${main_domain}
-
-    # Uncomment below if you want basic auth on UI and SMTP
-    #MP_UI_AUTH: mailpit:${default_password}
-    #MP_SMTP_AUTH: mailpit:${default_password}
-
-  mounts: []