fix: don't enable the bitcoin canister when --system-canisters is passed (#4410)

Author: raymondk

src/dfx/src/actors/pocketic.rs

@@ -395,7 +395,7 @@ async fn initialize_pocketic(
             sns: Some(IcpFeaturesConfig::default()),
             ii: Some(IcpFeaturesConfig::default()),
             nns_ui: Some(IcpFeaturesConfig::default()),
-            bitcoin: Some(IcpFeaturesConfig::default()),
+            bitcoin: None,
         })
     } else {
         None