Saner weights + lease calcuation fix. (#2778)

And have proper benchmarks.

---------

Co-authored-by: eskimor <eskimor@no-such-url.com>
Co-authored-by: command-bot <>
Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>

substrate/frame/broker/src/benchmarking.rs

@@ -885,6 +885,17 @@ mod benches {
 			T::Coretime::request_revenue_info_at(rc_block);
 		}
 	}
+	#[benchmark]
+	fn notify_core_count() -> Result<(), BenchmarkError> {
+		let admin_origin =
+			T::AdminOrigin::try_successful_origin().map_err(|_| BenchmarkError::Weightless)?;
+
+		#[extrinsic_call]
+		_(admin_origin as T::RuntimeOrigin, 100);
+
+		assert!(CoreCountInbox::<T>::take().is_some());
+		Ok(())
+	}
 
 	#[benchmark]
 	fn do_tick_base() -> Result<(), BenchmarkError> {