Replace isahc with async ureq (#18414)

REplace isahc with ureq everywhere gpui is used.

This should allow us to make http requests without libssl; and avoid a
long-tail of panics caused by ishac.

Release Notes:

- (potentially breaking change) updated our http client

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Co-authored-by: Mikayla <mikayla@zed.dev>

crates/collab/Cargo.toml

@@ -37,7 +37,7 @@ futures.workspace = true
 google_ai.workspace = true
 hex.workspace = true
 http_client.workspace = true
-isahc_http_client.workspace = true
+reqwest_client.workspace = true
 jsonwebtoken.workspace = true
 live_kit_server.workspace = true
 log.workspace = true