Enable clippy::needless_lifetimes (#8777)

This PR enables the
[`clippy::needless_lifetimes`](https://rust-lang.github.io/rust-clippy/master/index.html#/needless_lifetimes)
rule and fixes the outstanding violations.

Release Notes:

- N/A

crates/git/src/diff.rs

@@ -208,8 +208,8 @@ impl BufferDiff {
         }
     }
 
-    fn process_patch_hunk<'a>(
-        patch: &GitPatch<'a>,
+    fn process_patch_hunk(
+        patch: &GitPatch<'_>,
         hunk_index: usize,
         buffer: &text::BufferSnapshot,
         buffer_row_divergence: &mut i64,