Route all LLM traffic through cloud.zed.dev (#34404)

This PR makes it so all LLM traffic is routed through `cloud.zed.dev`.

We're already routing `llm.zed.dev` to `cloud.zed.dev` on the server,
but we want to standardize on `cloud.zed.dev` moving forward.

Release Notes:

- N/A

crates/zeta/src/zeta.rs

@@ -8,7 +8,6 @@ mod rate_completion_modal;
 
 pub(crate) use completion_diff_element::*;
 use db::kvp::KEY_VALUE_STORE;
-use feature_flags::{FeatureFlagAppExt as _, ZedCloudFeatureFlag};
 pub use init::*;
 use inline_completion::DataCollectionState;
 use license_detection::LICENSE_FILES_TO_CHECK;
@@ -391,7 +390,6 @@ impl Zeta {
         let client = self.client.clone();
         let llm_token = self.llm_token.clone();
         let app_version = AppVersion::global(cx);
-        let use_cloud = cx.has_flag::<ZedCloudFeatureFlag>();
 
         let buffer = buffer.clone();
 
@@ -482,7 +480,6 @@ impl Zeta {
                 llm_token,
                 app_version,
                 body,
-                use_cloud,
             })
             .await;
             let (response, usage) = match response {
@@ -748,7 +745,6 @@ and then another
                 llm_token,
                 app_version,
                 body,
-                use_cloud,
                 ..
             } = params;
 
@@ -764,7 +760,7 @@ and then another
                     } else {
                         request_builder.uri(
                             http_client
-                                .build_zed_llm_url("/predict_edits/v2", &[], use_cloud)?
+                                .build_zed_llm_url("/predict_edits/v2", &[])?
                                 .as_ref(),
                         )
                     };
@@ -824,7 +820,6 @@ and then another
         let client = self.client.clone();
         let llm_token = self.llm_token.clone();
         let app_version = AppVersion::global(cx);
-        let use_cloud = cx.has_flag::<ZedCloudFeatureFlag>();
         cx.spawn(async move |this, cx| {
             let http_client = client.http_client();
             let mut response = llm_token_retry(&llm_token, &client, |token| {
@@ -835,7 +830,7 @@ and then another
                     } else {
                         request_builder.uri(
                             http_client
-                                .build_zed_llm_url("/predict_edits/accept", &[], use_cloud)?
+                                .build_zed_llm_url("/predict_edits/accept", &[])?
                                 .as_ref(),
                         )
                     };
@@ -1131,7 +1126,6 @@ struct PerformPredictEditsParams {
     pub llm_token: LlmApiToken,
     pub app_version: SemanticVersion,
     pub body: PredictEditsBody,
-    pub use_cloud: bool,
 }
 
 #[derive(Error, Debug)]