vim S (#2929)

Release Notes:
- vim: Add `S` to substitute line ([#1897](https://github.com/zed-industries/community/issues/1897)).

crates/vim/src/test/neovim_connection.rs

@@ -237,6 +237,9 @@ impl NeovimConnection {
 
     #[cfg(not(feature = "neovim"))]
     pub async fn set_option(&mut self, value: &str) {
+        if let Some(NeovimData::Get { .. }) = self.data.front() {
+            self.data.pop_front();
+        };
         assert_eq!(
             self.data.pop_front(),
             Some(NeovimData::SetOption {