Remove unnecessary work from ps (#3407)

The ps plugin has an unnecessary call to `std:🧵:sleep(500ms)` that
delays runtime by 500ms. Additionally, there is a call to
`sysinfo::SystemExt::refresh_process`, which is not required as the previous
call to sysinfo::SystemExt::refresh_all handles the "refresh" of all processes
without a need to do this individually. Combining both of these improvements
means that running ps runs nearly instentaneously.

Fixes #3402

crates/nu_plugin_ps/src/ps.rs

@@ -15,15 +15,12 @@ impl Ps {
 pub async fn ps(tag: Tag, long: bool) -> Result<Vec<Value>, ShellError> {
     let mut sys = System::new_all();
     sys.refresh_all();
-    let duration = std::time::Duration::from_millis(500);
-    std::thread::sleep(duration);
 
     let mut output = vec![];
 
     let result: Vec<_> = sys.get_processes().iter().map(|x| *x.0).collect();
 
     for pid in result.into_iter() {
-        sys.refresh_process(pid);
         if let Some(result) = sys.get_process(pid) {
             let mut dict = TaggedDictBuilder::new(&tag);
             dict.insert_untagged("pid", UntaggedValue::int(pid));