Avoid asyncio-dangling-task for nonlocal and global bindings

crates/ruff_linter/resources/test/fixtures/ruff/RUF006.py

@@ -152,3 +152,13 @@ async def f(x: bool):
         t = asyncio.create_task(asyncio.sleep(1))
     else:
         t = None
+
+
+# OK
+async def f(x: bool):
+    global T
+
+    if x:
+        T = asyncio.create_task(asyncio.sleep(1))
+    else:
+        T = None

crates/ruff_linter/src/rules/ruff/rules/asyncio_dangling_task.rs

@@ -112,11 +112,15 @@ pub(crate) fn asyncio_dangling_binding(
     for binding_id in scope.binding_ids() {
         // If the binding itself is used, or it's not an assignment, skip it.
         let binding = semantic.binding(binding_id);
-        if binding.is_used() || !binding.kind.is_assignment() {
+        if binding.is_used()
+            || binding.is_global()
+            || binding.is_nonlocal()
+            || !binding.kind.is_assignment()
+        {
             continue;
         }
 
-        // Otherwise, any dangling tasks, including those that are shadowed, as in:
+        // Otherwise, flag any dangling tasks, including those that are shadowed, as in:
         // ```python
         // if x > 0:
         //     task = asyncio.create_task(make_request())
@@ -127,7 +131,11 @@ pub(crate) fn asyncio_dangling_binding(
             std::iter::successors(Some(binding_id), |id| semantic.shadowed_binding(*id))
         {
             let binding = semantic.binding(binding_id);
-            if binding.is_used() || !binding.kind.is_assignment() {
+            if binding.is_used()
+                || binding.is_global()
+                || binding.is_nonlocal()
+                || !binding.kind.is_assignment()
+            {
                 continue;
             }