Remove empty config files

Remove empty config files:
* config/packages/prod/deprecations.yaml
* config/packages/prod/webpack_encore.yaml
* config/packages/test/webpack_encore.yaml

This fixes the `yml/no-empty-document` eslint rule errors.

Bug: T421660

Author: okerekechinweotito

.eslintrc.json

@@ -12,7 +12,6 @@
 		"sourceType": "module"
 	},
 	"rules": {
-		"no-jquery/no-global-selector": "warn",
-		"yml/no-empty-document": "warn"
+		"no-jquery/no-global-selector": "warn"
 	}
 }