Add a test demonstrating ERB language loading bug (#32278)

Fixes https://github.com/zed-industries/zed/issues/12174

Release Notes:

- Fixed a bug where ERB files were not parsed correctly when the
languages were initially loaded.
72de3143c8Max Brunsfeld committed on 6/11/2025, 4:03:42 AM· committed by GitHubparentad206a6
4 files changedLine totals unavailable