Fix stalled pipe on Windows when using target quality (#596)

* Fix stalled pipe on Windows when using target quality (#551)

I haven't seen any reports of this being an issue on Linux, so this will only affect Windows builds for the time being

* fix formatting

* fix formatting (again)

gh actions should've let me off the hook for this silly oversight

Author: woot000

av1an-core/src/target_quality.rs

@@ -187,7 +187,11 @@ impl<'a> TargetQuality<'a> {
       let mut source = if let [pipe_cmd, args @ ..] = &*chunk.source {
         tokio::process::Command::new(pipe_cmd)
           .args(args)
-          .stderr(Stdio::piped())
+          .stderr(if cfg!(windows) {
+            Stdio::null()
+          } else {
+            Stdio::piped()
+          })
           .stdout(Stdio::piped())
           .spawn()
           .unwrap()
@@ -202,7 +206,11 @@ impl<'a> TargetQuality<'a> {
           .args(args)
           .stdin(source_pipe_stdout)
           .stdout(Stdio::piped())
-          .stderr(Stdio::piped())
+          .stderr(if cfg!(windows) {
+            Stdio::null()
+          } else {
+            Stdio::piped()
+          })
           .spawn()
           .unwrap()
       } else {
@@ -216,7 +224,11 @@ impl<'a> TargetQuality<'a> {
           .args(args.iter().map(AsRef::as_ref))
           .stdin(source_pipe_stdout)
           .stdout(Stdio::piped())
-          .stderr(Stdio::piped())
+          .stderr(if cfg!(windows) {
+            Stdio::null()
+          } else {
+            Stdio::piped()
+          })
           .spawn()
           .unwrap()
       } else {