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/coder/template.yml

@@ -1,18 +0,0 @@
-variables:
-  main_domain: ${domain}
-  postgres_password: ${password}
-
-config:
-  domains:
-    - serviceName: coder
-      port: 7080
-      host: ${main_domain}
-
-  env:
-    - CODER_ACCESS_URL=
-    - CODER_HTTP_ADDRESS=0.0.0.0:7080
-    - POSTGRES_DB=coder
-    - POSTGRES_USER=coder
-    - POSTGRES_PASSWORD=${postgres_password}
-
-  mounts: []