Fix interaction with Anthropic models when using it via zed.dev (#15009)

Release Notes:

- N/A

---------

Co-authored-by: Bennet <bennet@zed.dev>

crates/language_model/src/model/cloud_model.rs

@@ -1,4 +1,3 @@
-use crate::LanguageModelRequest;
 pub use anthropic::Model as AnthropicModel;
 pub use ollama::Model as OllamaModel;
 pub use open_ai::Model as OpenAiModel;
@@ -88,19 +87,4 @@ impl CloudModel {
             Self::Custom { max_tokens, .. } => max_tokens.unwrap_or(200_000),
         }
     }
-
-    pub fn preprocess_request(&self, request: &mut LanguageModelRequest) {
-        match self {
-            Self::Claude3Opus
-            | Self::Claude3Sonnet
-            | Self::Claude3Haiku
-            | Self::Claude3_5Sonnet => {
-                request.preprocess_anthropic();
-            }
-            Self::Custom { name, .. } if name.starts_with("anthropic/") => {
-                request.preprocess_anthropic();
-            }
-            _ => {}
-        }
-    }
 }