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

---------

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

crates/extension/Cargo.toml

@@ -56,10 +56,12 @@ task.workspace = true
 serde_json_lenient.workspace = true
 
 [dev-dependencies]
-isahc_http_client.workspace = true
+ureq_client.workspace = true
 ctor.workspace = true
 env_logger.workspace = true
 parking_lot.workspace = true
+reqwest_client.workspace = true
+tokio.workspace = true
 
 fs = { workspace = true, features = ["test-support"] }
 gpui = { workspace = true, features = ["test-support"] }