fix `await null` in forEach

Benchmark goes from ~54ms to ~33ms

pkgs/pool/CHANGELOG.md

diff --git a/pkgs/pool/CHANGELOG.md b/pkgs/pool/CHANGELOG.md
index 0c3d314..c680dd2 100644
--- a/pkgs/pool/CHANGELOG.md
+++ b/pkgs/pool/CHANGELOG.md
@@ -1,3 +1,8 @@
+## 1.4.1
+
+* `forEach`: Avoid `await null` if the `Stream` is not paused.
+  Improves trivial benchmark by 40%. 
+
 ## 1.4.0
 
 * Add `forEach` to `Pool` to support efficient async processing of an

pkgs/pool/lib/pool.dart

diff --git a/pkgs/pool/lib/pool.dart b/pkgs/pool/lib/pool.dart
index 779300e..12dd5e1 100644
--- a/pkgs/pool/lib/pool.dart
+++ b/pkgs/pool/lib/pool.dart
@@ -170,7 +170,9 @@
 
         _resetTimer();
 
-        await resumeCompleter?.future;
+        if (resumeCompleter != null) {
+          await resumeCompleter.future;
+        }
 
         if (cancelPending) {
           break;

pkgs/pool/pubspec.yaml

diff --git a/pkgs/pool/pubspec.yaml b/pkgs/pool/pubspec.yaml
index 35fb62d..ebb05d9 100644
--- a/pkgs/pool/pubspec.yaml
+++ b/pkgs/pool/pubspec.yaml
@@ -1,5 +1,5 @@
 name: pool
-version: 1.4.0
+version: 1.4.1-dev
 
 description: >-
   Manage a finite pool of resources.