http_client: Add integrity checks for GitHub binaries using digest checks (#43737)

Generalizes the digest verification logic from `rust-analyzer` and
`clangd` into a reusable helper function in
`http_client::github_download`.

This removes ~100 lines of duplicated code across the two language
adapters and makes it easier for other language servers to adopt digest
verification in the future.

Closes #35201

Release Notes:

- N/A
05764e8af7Tom Planche committed on 12/1/2025, 8:00:27 AM· committed by GitHubparentdb86feb
3 files changedLine totals unavailable