fix: monitorUpstreamConnectionState CPU consumption (#3884)

* fix: monitorUpstreamConnectionState CPU consumption

`monitorUpstreamConnectionState()` is a goroutine that listens for GRPC client connection changes using GRPC's `WaitForStateChange` method. `monitorUpstreamConnectionState()` was consuming the a lot of CPU. It was continuously running and not actually waiting for state changes. The `state` for `monitorUpstreamConnectionState()` was not getting correctly updated which caused the loop to continuously run instead of waiting for new state changes.

Update GRPC `WaitForStateChange` method to use the same `state` that gets updated.

CHANGELOG.md

@@ -4,6 +4,9 @@ Canonical reference for changes, improvements, and bugfixes for Boundary.
 
 ## Next
 
+### Bug Fixes
+* monitorUpstreamConnectionState CPU consumption: `monitorUpstreamConnectionState()` is a goroutine that listens for GRPC client connection changes using GRPC's `WaitForStateChange` method. `monitorUpstreamConnectionState()` was consuming the a lot of CPU. It was continuously running and not actually waiting for state changes. The `state` for `monitorUpstreamConnectionState()` was not getting correctly updated which caused the loop to continuously run instead of waiting for new state changes.
+
 ## 0.14.1 (2023/10/17)
 
 ### Security

internal/daemon/worker/controller_connection.go

@@ -434,13 +434,13 @@ func monitorUpstreamConnectionState(ctx context.Context, cc *grpc.ClientConn, co
 	}
 
 	for cc.WaitForStateChange(ctx, state) {
-		newState := cc.GetState()
+		state = cc.GetState()
 
 		// if the client is shutdown, exit function
-		if newState == connectivity.Shutdown {
+		if state == connectivity.Shutdown {
 			return
 		}
 
-		connectionState.Store(newState)
+		connectionState.Store(state)
 	}
 }