firestore-compat: fix typing error in fields.test.ts: TS2339: Property 'ignoreUndefinedProperties' does not exist on type '{ host: string; ssl: boolean; }' (#7108)

Author: dconeybe

packages/firestore-compat/test/fields.test.ts

@@ -387,8 +387,7 @@ apiDescribe('Timestamp Fields in snapshots', (persistence: boolean) => {
 });
 
 apiDescribe('`undefined` properties', (persistence: boolean) => {
-  const settings = { ...DEFAULT_SETTINGS };
-  settings.ignoreUndefinedProperties = true;
+  const settings = { ...DEFAULT_SETTINGS, ignoreUndefinedProperties: true };
 
   it('are ignored in set()', () => {
     return withTestDocAndSettings(persistence, settings, async doc => {