zephyr: embassy: Add Default implementation

Clippy complains about a no-argument `new()` method without an
accompanying Default.  It doesn't hurt anything to add, and could make
this potentially slightly more useful.

Signed-off-by: David Brown <[email protected]>

Author: d3zd3z

zephyr/src/embassy/executor.rs

@@ -52,6 +52,12 @@ impl Executor {
     }
 }
 
+impl Default for Executor {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 #[export_name = "__pender"]
 fn __pender(context: *mut ()) {
     unsafe {