Remove now unnecessary explicit dyn casts

Rust-analyzer used to not infer this, seems like now it does.

plugins/examples/stft/src/lib.rs

@@ -96,8 +96,7 @@ impl Plugin for Stft {
     const SAMPLE_ACCURATE_AUTOMATION: bool = true;
 
     fn params(&self) -> Arc<dyn Params> {
-        // The explicit cast is not needed, but Rust Analyzer gets very upset when you don't do it
-        self.params.clone() as Arc<dyn Params>
+        self.params.clone()
     }
 
     fn accepts_bus_config(&self, config: &BusConfig) -> bool {