Make Buffer::apply_ops infallible (#18089)

This PR makes the `Buffer::apply_ops` method infallible for
`text::Buffer` and `language::Buffer`.

We discovered that `text::Buffer::apply_ops` was only fallible due to
`apply_undo`, which didn't actually need to be fallible.

Release Notes:

- N/A

crates/language/src/buffer.rs

@@ -1972,7 +1972,7 @@ impl Buffer {
         &mut self,
         ops: I,
         cx: &mut ModelContext<Self>,
-    ) -> Result<()> {
+    ) {
         self.pending_autoindent.take();
         let was_dirty = self.is_dirty();
         let old_version = self.version.clone();
@@ -1991,14 +1991,13 @@ impl Buffer {
                 }
             })
             .collect::<Vec<_>>();
-        self.text.apply_ops(buffer_ops)?;
+        self.text.apply_ops(buffer_ops);
         self.deferred_ops.insert(deferred_ops);
         self.flush_deferred_ops(cx);
         self.did_edit(&old_version, was_dirty, cx);
         // Notify independently of whether the buffer was edited as the operations could include a
         // selection update.
         cx.notify();
-        Ok(())
     }
 
     fn flush_deferred_ops(&mut self, cx: &mut ModelContext<Self>) {