Revert "Multiple priority scheduler" (#44637)

Reverts zed-industries/zed#44575

crates/worktree/src/worktree.rs

@@ -22,8 +22,7 @@ use git::{
     COMMIT_MESSAGE, DOT_GIT, FSMONITOR_DAEMON, GITIGNORE, INDEX_LOCK, LFS_DIR, status::GitSummary,
 };
 use gpui::{
-    App, AppContext as _, AsyncApp, BackgroundExecutor, Context, Entity, EventEmitter, Priority,
-    Task,
+    App, AppContext as _, AsyncApp, BackgroundExecutor, Context, Entity, EventEmitter, Task,
 };
 use ignore::IgnoreStack;
 use language::DiskState;
@@ -4124,7 +4123,7 @@ impl BackgroundScanner {
 
         let progress_update_count = AtomicUsize::new(0);
         self.executor
-            .scoped_priority(Priority::Low, |scope| {
+            .scoped(|scope| {
                 for _ in 0..self.executor.num_cpus() {
                     scope.spawn(async {
                         let mut last_progress_update_count = 0;