Update dependencies, remove unused dependencies

Create configuration files for updated eslint and prettier packages.
Remove eslint configuration section from package.json.

Remove unneeded eslint-ignore directives from source files.

The @types/node package has a newer major version available, but 20 is
the newest LTS version, so the package is kept there for now.

.prettierrc

@@ -0,0 +1,7 @@
+{
+  "endOfLine": "lf",
+  "semi": false,
+  "singleQuote": false,
+  "tabWidth": 2,
+  "trailingComma": "es5"
+}

eslint.config.mjs

@@ -0,0 +1,38 @@
+import tsParser from '@typescript-eslint/parser';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+import js from '@eslint/js';
+import { FlatCompat } from '@eslint/eslintrc';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+const compat = new FlatCompat({
+  baseDirectory: __dirname,
+  recommendedConfig: js.configs.recommended,
+  allConfig: js.configs.all
+});
+
+export default [
+  {
+    ignores: [
+      'node_modules/',
+      'lib/'
+    ]
+  },
+  ...compat.extends('plugin:@typescript-eslint/recommended', 'prettier'),
+  {
+    languageOptions: {
+      parser: tsParser,
+      ecmaVersion: 2018,
+      sourceType: 'module'
+    },
+
+    rules: {
+      '@typescript-eslint/ban-ts-comment': 'off',
+      '@typescript-eslint/explicit-function-return-type': 'off',
+      '@typescript-eslint/no-empty-function': 'off',
+      '@typescript-eslint/no-explicit-any': 'off',
+      '@typescript-eslint/no-unsafe-declaration-merging': 'off'
+    }
+  }
+];