Also add proxy to zed http client (#7184)

Follow up to #6765 because I couldn't figure out how to add to that PR.

Release Notes:

- N/A

crates/util/src/http.rs

@@ -44,6 +44,7 @@ pub fn zed_client(zed_host: &str) -> Arc<ZedHttpClient> {
             isahc::HttpClient::builder()
                 .connect_timeout(Duration::from_secs(5))
                 .low_speed_timeout(100, Duration::from_secs(5))
+                .proxy(http_proxy_from_env())
                 .build()
                 .unwrap(),
         ),