Enable Claude 3 models to be used via the Zed server if "language-models" feature flag is enabled for user (#10015)

Release Notes:

- N/A

crates/collab/src/lib.rs

@@ -134,6 +134,7 @@ pub struct Config {
     pub zed_environment: Arc<str>,
     pub openai_api_key: Option<Arc<str>>,
     pub google_ai_api_key: Option<Arc<str>>,
+    pub anthropic_api_key: Option<Arc<str>>,
     pub zed_client_checksum_seed: Option<String>,
     pub slack_panics_webhook: Option<String>,
     pub auto_join_channel_id: Option<ChannelId>,