Verify downloaded rust-analyzer and clang binaries by checking the artifact digest (#35642)

Release Notes:

- Added GitHub artifact digest verification for rust-analyzer and clangd
binary downloads, skipping downloads if cached binary digest is up to
date
- Added verification that cached rust-analyzer and clangd binaries are
executable, if not they are redownloaded

---------

Co-authored-by: Kirill Bulatov <kirill@zed.dev>

crates/languages/Cargo.toml

@@ -36,6 +36,7 @@ load-grammars = [
 [dependencies]
 anyhow.workspace = true
 async-compression.workspace = true
+async-fs.workspace = true
 async-tar.workspace = true
 async-trait.workspace = true
 chrono.workspace = true
@@ -62,6 +63,7 @@ regex.workspace = true
 rope.workspace = true
 rust-embed.workspace = true
 schemars.workspace = true
+sha2.workspace = true
 serde.workspace = true
 serde_json.workspace = true
 serde_json_lenient.workspace = true
@@ -69,6 +71,7 @@ settings.workspace = true
 smol.workspace = true
 snippet_provider.workspace = true
 task.workspace = true
+tempfile.workspace = true
 toml.workspace = true
 tree-sitter = { workspace = true, optional = true }
 tree-sitter-bash = { workspace = true, optional = true }