lsp: Check for existing snapshots before sending off a didOpen notification (#25409)

Closes #ISSUE

Release Notes:

- Fixed Zed sending out didOpen notification to a language server when
opening documents.

crates/project/src/lsp_store.rs

@@ -1921,11 +1921,13 @@ impl LocalLspStore {
                     version: 0,
                     snapshot: initial_snapshot.clone(),
                 };
-                self.buffer_snapshots
+                let previous_snapshots = self
+                    .buffer_snapshots
                     .entry(buffer_id)
                     .or_default()
                     .insert(server.server_id(), vec![snapshot]);
 
+                if previous_snapshots.is_none() {
                     server.register_buffer(
                         uri.clone(),
                         adapter.language_id(&language.name()),
@@ -1935,6 +1937,7 @@ impl LocalLspStore {
                 }
             }
         }
+    }
 
     pub(crate) fn unregister_old_buffer_from_language_servers(
         &mut self,