Fix linter resolutions

Restore the use of TypeScript project references to the TypeScript
ESLint plugin. Move the optimal-select module declaration to the root of
the dom package, where TypeScript will automatically find it. Disable
the import/no-unresolved rule for TypeScript files because TypeScript
itself will check that modules resolve.

Author: tilgovi

.eslintrc.js

@@ -108,9 +108,11 @@ module.exports = {
         ecmaVersion: 2020,
         project: ['./tsconfig.test.json', './packages/*/tsconfig.json'],
         tsconfigRootDir: __dirname,
+        EXPERIMENTAL_useSourceOfProjectReferenceRedirect: true,
       },
       plugins: ['@typescript-eslint'],
       rules: {
+        'import/no-unresolved': 'off',
         '@typescript-eslint/consistent-type-imports': 'error',
         '@typescript-eslint/no-duplicate-imports': 'error',
         '@typescript-eslint/no-explicit-any': 'off',

packages/dom/@types/optimal-select/index.d.ts renamed to packages/dom/src/optimal-select.d.ts

@@ -1,6 +1,6 @@
 {
   "extends": "../../tsconfig.base.json",
-  "include": ["src", "./@types"],
+  "include": ["src"],
   "compilerOptions": {
     "outDir": "lib",
     "rootDir": "src"