chore: Bump Rust version to 1.88 (#33439)

Goodies in this version:
- if-let chains 🎉
- Better compiler perf for Zed
(https://github.com/rust-lang/rust/pull/138522)

For more, see: https://releases.rs/docs/1.88.0/

Release Notes:

- N/A

---------

Co-authored-by: Junkui Zhang <364772080@qq.com>

crates/project/src/git_store.rs

@@ -4556,7 +4556,9 @@ async fn compute_snapshot(
     let mut events = Vec::new();
     let branches = backend.branches().await?;
     let branch = branches.into_iter().find(|branch| branch.is_head);
-    let statuses = backend.status(&[WORK_DIRECTORY_REPO_PATH.clone()]).await?;
+    let statuses = backend
+        .status(std::slice::from_ref(&WORK_DIRECTORY_REPO_PATH))
+        .await?;
     let statuses_by_path = SumTree::from_iter(
         statuses
             .entries

crates/project/src/git_store/conflict_set.rs

@@ -565,7 +565,7 @@ mod tests {
             conflict_set.snapshot().conflicts[0].clone()
         });
         cx.update(|cx| {
-            conflict.resolve(buffer.clone(), &[conflict.theirs.clone()], cx);
+            conflict.resolve(buffer.clone(), std::slice::from_ref(&conflict.theirs), cx);
         });
 
         cx.run_until_parked();

crates/project/src/lsp_store.rs

@@ -5743,7 +5743,10 @@ impl LspStore {
                 match language {
                     Some(language) => {
                         adapter
-                            .labels_for_completions(&[completion_item.clone()], language)
+                            .labels_for_completions(
+                                std::slice::from_ref(&completion_item),
+                                language,
+                            )
                             .await?
                     }
                     None => Vec::new(),

crates/project/src/project_tests.rs

@@ -7502,13 +7502,13 @@ async fn test_staging_random_hunks(
         if hunk.status().has_secondary_hunk() {
             log::info!("staging hunk at {row}");
             uncommitted_diff.update(cx, |diff, cx| {
-                diff.stage_or_unstage_hunks(true, &[hunk.clone()], &snapshot, true, cx);
+                diff.stage_or_unstage_hunks(true, std::slice::from_ref(hunk), &snapshot, true, cx);
             });
             hunk.secondary_status = SecondaryHunkRemovalPending;
         } else {
             log::info!("unstaging hunk at {row}");
             uncommitted_diff.update(cx, |diff, cx| {
-                diff.stage_or_unstage_hunks(false, &[hunk.clone()], &snapshot, true, cx);
+                diff.stage_or_unstage_hunks(false, std::slice::from_ref(hunk), &snapshot, true, cx);
             });
             hunk.secondary_status = SecondaryHunkAdditionPending;
         }