Eslint: Restore curly rule when using prettier

The `curly` eslint rule was disabled when using prettier. Some
configurations of the rule may conflict with prettier's autoformatting,
but the `all` option used in @wordpress/eslint-plugin does not.

This aligns with the WordPress JavaScript Standards:

> `if`, `else`, `for`, `while`, and `try` blocks should always use
> braces, and always go on multiple lines.

- WordPress JavaScript Standards: https://developer.wordpress.org/coding-standards/wordpress-coding-standards/javascript/#blocks-and-curly-braces
- `curly` rule description: https://eslint.org/docs/latest/rules/curly#rule-details

Co-authored-by: sirreal <jonsurrell@git.wordpress.org>
Co-authored-by: gziolo <gziolo@git.wordpress.org>
Co-authored-by: swissspidy <swissspidy@git.wordpress.org>
Co-authored-by: youknowriad <youknowriad@git.wordpress.org>

packages/eslint-plugin/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## Unreleased
 
+### Breaking Changes
+
+-   Enable `curly` eslint rule when using prettier ([#61204](https://github.com/WordPress/gutenberg/pull/61204)).
+
 ## 17.13.0 (2024-04-19)
 
 ## 17.12.0 (2024-04-03)

packages/eslint-plugin/configs/recommended.js

@@ -25,6 +25,12 @@ if ( isPackageInstalled( 'prettier' ) ) {
 	const prettierConfig = { ...defaultPrettierConfig, ...localPrettierConfig };
 	config.rules = {
 		'prettier/prettier': [ 'error', prettierConfig ],
+		// Prettier _disables_ this rule, but we want it!
+		// See https://github.com/prettier/eslint-config-prettier?tab=readme-ov-file#curly
+		// > This rule requires certain options.
+		// > …
+		// > If you like this rule, it can be used just fine with Prettier as long as you don’t use the "multi-line" or "multi-or-nest" option.
+		curly: [ 'error', 'all' ],
 	};
 }