chore: update eslint to disallow floating promises

src/GroundsForSupport.Client/eslint.config.js

@@ -9,10 +9,20 @@ import { defineConfig, globalIgnores } from 'eslint/config';
 export default defineConfig([
   globalIgnores(['dist']),
   {
+    rules: {
+      '@typescript-eslint/no-floating-promises': 'error',
+    },
     files: ['**/*.{ts,tsx}'],
     extends: [
       js.configs.recommended,
-      tseslint.configs.recommended,
+      tseslint.configs.recommendedTypeChecked,
+      {
+        languageOptions: {
+          parserOptions: {
+            projectService: true,
+          },
+        },
+      },
       reactHooks.configs.flat.recommended,
       reactRefresh.configs.vite,
     ],