refactor: clippy fix

new clippy rule broke ci

src/segment/block_index/writer.rs

@@ -17,7 +17,7 @@ fn concat_files<P: AsRef<Path>>(src_path: P, dest_path: P) -> crate::Result<()>
     let mut reader = BufReader::new(reader);
 
     let writer = OpenOptions::new()
-        .write(true)
+
         .create(true)
         .append(true)
         .open(dest_path)?;

src/snapshot.rs

@@ -308,7 +308,7 @@ impl Snapshot {
     ///
     /// This operation scans the entire tree: O(n) complexity!
     ///
-    /// Never, under any circumstances, use .len() == 0 to check
+    /// Never, under any circumstances, use .`len()` == 0 to check
     /// if the snapshot is empty, use [`Snapshot::is_empty`] instead.
     ///
     /// # Examples

src/tree.rs

@@ -317,7 +317,7 @@ impl Tree {
     ///
     /// This operation scans the entire tree: O(n) complexity!
     ///
-    /// Never, under any circumstances, use .len() == 0 to check
+    /// Never, under any circumstances, use .`len()` == 0 to check
     /// if the tree is empty, use [`Tree::is_empty`] instead.
     ///
     /// # Examples