language: Fix flaky bracket range deduplication test (#62996)
Noticed this in [this CI
run](https://github.com/zed-industries/zed/actions/runs/32452508104/job/96683569873?pr=62989).
The test now waits for parsing before taking its snapshot.
Release Notes:
- N/A
ab208db8d2Smit Barmase committed on 8/21/2026, 10:04:18 AM· committed by GitHubparent54230ad