Bundle editing workflow prompt as a read-only built-in prompt (#15615)

Built-in prompts can still be removed from the default prompt, but they
can't be edited and are automatically updated with new Zed releases.

Release Notes:

- N/A

---------

Co-authored-by: Antonio <antonio@zed.dev>

crates/assistant/src/context.rs

@@ -1386,7 +1386,7 @@ impl Context {
             async move {
                 let prompt_store = cx.update(|cx| PromptStore::global(cx))?.await?;
 
-                let mut prompt = prompt_store.operations_prompt();
+                let mut prompt = prompt_store.step_resolution_prompt();
                 prompt.push_str(&step_text);
 
                 request.messages.push(LanguageModelRequestMessage {