search: Add heuristic for discarding matching of binary files (#23581)

Fixes #23398 
Closes #23398

We'll bail on searches of files that we know are binary (thus even if we
were to find a match in them, they'd be thrown away by buffer loader).

Release Notes:

- Improved project search performance in worktrees with binary files

crates/fs/src/fs.rs

@@ -101,7 +101,7 @@ pub trait Fs: Send + Sync {
         self.remove_file(path, options).await
     }
     async fn open_handle(&self, path: &Path) -> Result<Arc<dyn FileHandle>>;
-    async fn open_sync(&self, path: &Path) -> Result<Box<dyn io::Read>>;
+    async fn open_sync(&self, path: &Path) -> Result<Box<dyn io::Read + Send + Sync>>;
     async fn load(&self, path: &Path) -> Result<String> {
         Ok(String::from_utf8(self.load_bytes(path).await?)?)
     }
@@ -499,7 +499,7 @@ impl Fs for RealFs {
         Ok(())
     }
 
-    async fn open_sync(&self, path: &Path) -> Result<Box<dyn io::Read>> {
+    async fn open_sync(&self, path: &Path) -> Result<Box<dyn io::Read + Send + Sync>> {
         Ok(Box::new(std::fs::File::open(path)?))
     }
 
@@ -1746,7 +1746,7 @@ impl Fs for FakeFs {
         Ok(())
     }
 
-    async fn open_sync(&self, path: &Path) -> Result<Box<dyn io::Read>> {
+    async fn open_sync(&self, path: &Path) -> Result<Box<dyn io::Read + Send + Sync>> {
         let bytes = self.load_internal(path).await?;
         Ok(Box::new(io::Cursor::new(bytes)))
     }