worker/errors: consider dep errors as 4xx status

All dependency errors, whether they are 4xx or 5xx,
are currently being considered as a 5xx error in parent
jobs. This is causing some of the build alerts to fire
off when a depsolve job has failed, for example, when
in reality, this is an expected result. This commit
ensures that dependency errors are being reported as
4xx status in monitoring.

internal/worker/clienterrors/errors.go

@@ -64,8 +64,12 @@ func GetStatusCode(err *Error) StatusCode {
 		return JobStatusUserInputError
 	case ErrorInvalidTarget:
 		return JobStatusUserInputError
+	case ErrorDepsolveDependency:
+		return JobStatusUserInputError
+	case ErrorManifestDependency:
+		return JobStatusUserInputError
 	case ErrorEmptyManifest:
-		return JobStatusInternalError
+		return JobStatusUserInputError
 	default:
 		return JobStatusInternalError
 	}