Use Instant not chrono for telemetry (#20756)

We occasionally see dates in the future appearing in our telemetry. One
hypothesis is that this is caused by a clock change while Zed is running
causing date math based on chrono to be incorrect.

Instant *should* be a more stable source of relative timestamps.

Release Notes:

- N/A

crates/workspace/src/workspace.rs

@@ -606,7 +606,7 @@ impl AppState {
 
         let fs = fs::FakeFs::new(cx.background_executor().clone());
         let languages = Arc::new(LanguageRegistry::test(cx.background_executor().clone()));
-        let clock = Arc::new(clock::FakeSystemClock::default());
+        let clock = Arc::new(clock::FakeSystemClock::new());
         let http_client = http_client::FakeHttpClient::with_404_response();
         let client = Client::new(clock, http_client.clone(), cx);
         let session = cx.new_model(|cx| AppSession::new(Session::test(), cx));