python: Fix flickering in the status bar (#36039)

- **util: Have maybe! use async closures instead of async blocks**
- **python: Fix flickering of virtual environment indicator in status
bar**

Closes #30723

Release Notes:

- Python: Fixed flickering of the status bar virtual environment
indicator

---------

Co-authored-by: Lukas Wirth <lukas@zed.dev>

crates/util/src/util.rs

@@ -887,10 +887,10 @@ macro_rules! maybe {
         (|| $block)()
     };
     (async $block:block) => {
-        (|| async $block)()
+        (async || $block)()
     };
     (async move $block:block) => {
-        (|| async move $block)()
+        (async move || $block)()
     };
 }