Improve when the commit suggestions would show (#26313)

Release Notes:

- Git Beta: Fixed a few bugs where the suggested commit text wouldn't
show in certain cases, or would update slowly.

crates/worktree/src/worktree.rs

@@ -3960,10 +3960,6 @@ pub struct StatusEntry {
 }
 
 impl StatusEntry {
-    pub fn is_staged(&self) -> Option<bool> {
-        self.status.is_staged()
-    }
-
     fn to_proto(&self) -> proto::StatusEntry {
         let simple_status = match self.status {
             FileStatus::Ignored | FileStatus::Untracked => proto::GitStatus::Added as i32,