Fail early if clangd is downloaded on aarch Linux (#46346)

Part of https://github.com/zed-industries/zed/issues/46182

One caveat of this fix is that already downloaded clangd versions will
error with the old, "cannot start binary" error.
The new ones will be getting

<img width="1728" height="1084" alt="image"
src="https://github.com/user-attachments/assets/d2fdafed-6e60-4bc6-9eb2-b785fff65f3a"
/>

though.

Release Notes:

- N/A
f599864294Kirill Bulatov committed on 1/8/2026, 11:05:15 AM· committed by GitHubparent4c46872
1 file changedLine totals unavailable