fix(net)!: remove Drop assertions for any unused plans

Tests should use the existing `assert_no_unused_plans` method available
on both `Net` and `MockNet`.

This removes the problem of assetions being applied early when there are
multiple clones of the `Net` or `MockNet` and one of them is dropped.

src/net/system.rs

@@ -628,47 +628,6 @@ impl From<MockNet> for Net {
     }
 }
 
-impl Drop for MockNet {
-    #[cfg_attr(test, mutants::skip)]
-    #[tracing::instrument]
-    fn drop(&mut self) {
-        // Don't assert during panic to avoid double panic
-        if std::thread::panicking() {
-            return;
-        }
-        let unused = self.plans.take();
-        if !unused.is_empty() {
-            log_unused_plans(&unused);
-            assert!(
-                unused.is_empty(),
-                "{} expected requests were not made",
-                unused.len()
-            );
-        }
-    }
-}
-impl Drop for Net {
-    #[cfg_attr(test, mutants::skip)]
-    #[tracing::instrument]
-    fn drop(&mut self) {
-        // Don't assert during panic to avoid double panic
-        if std::thread::panicking() {
-            return;
-        }
-        if let Some(plans) = &self.plans {
-            let unused = plans.try_lock().expect("lock plans").take();
-            if !unused.is_empty() {
-                log_unused_plans(&unused);
-                assert!(
-                    unused.is_empty(),
-                    "{} expected requests were not made",
-                    unused.len()
-                );
-            }
-        }
-    }
-}
-
 #[cfg_attr(test, mutants::skip)]
 fn log_unused_plans(unused: &[Plan]) {
     if !unused.is_empty() {