chore: update ESLint to v9

eslint.config.mjs

@@ -0,0 +1,47 @@
+import pluginJs from '@eslint/js';
+import imports from 'eslint-plugin-import';
+import jestConfig from 'eslint-plugin-jest';
+import node from 'eslint-plugin-n';
+import globals from 'globals';
+import tsEslint from 'typescript-eslint';
+
+/** @type {import('eslint').Linter.Config[]} */
+export default [
+  { files: ['**/*.{js,mjs,cjs,ts}'] },
+  {
+    ignores: ['dist', 'contracts', 'typechain', 'node_modules'],
+  },
+  { languageOptions: { globals: globals.node } },
+
+  pluginJs.configs.recommended,
+  ...tsEslint.configs.recommended,
+  imports.flatConfigs.errors,
+  imports.flatConfigs.warnings,
+  imports.flatConfigs.typescript,
+  node.configs['flat/recommended'],
+  jestConfig.configs['flat/recommended'],
+
+  {
+    rules: {
+      'jest/expect-expect': 'off',
+      'jest/no-conditional-expect': 'off',
+
+      'n/no-missing-import': 'off',
+      'n/no-extraneous-import': 'off',
+      'n/no-unsupported-features/es-syntax': 'off',
+
+      '@typescript-eslint/no-explicit-any': 'off',
+      '@typescript-eslint/no-empty-function': 'off',
+      '@typescript-eslint/no-non-null-assertion': 'off',
+      '@typescript-eslint/adjacent-overload-signatures': 'off',
+      '@typescript-eslint/no-unsafe-declaration-merging': 'off',
+
+      'import/no-unresolved': 'off',
+
+      semi: 'error',
+      'no-trailing-spaces': 'error',
+      'no-unexpected-multiline': 'off',
+      quotes: ['error', 'single', { avoidEscape: true }],
+    },
+  },
+];