Update Sources/Prometheus/MetricTypes/Summary.swift

No need to name closure arguments

Co-Authored-By: Yasumoto <[email protected]>

Author: MrLotU

Sources/Prometheus/MetricTypes/Summary.swift

@@ -125,7 +125,7 @@ public class Summary<NumType: DoubleRepresentable, Labels: SummaryLabels>: Metri
     ///     - labels: Labels to attach to the observed value
     ///     - done: Completion handler
     ///     - observedValue: Value written to the summary
-    public func observe(_ value: NumType, _ labels: Labels? = nil, _ done: @escaping (_ observedValue: NumType) -> Void = { _ in }) {
+    public func observe(_ value: NumType, _ labels: Labels? = nil, _ done: @escaping () -> Void = { }) {
         prometheusQueue.async(flags: .barrier) {
             if let labels = labels, type(of: labels) != type(of: EmptySummaryLabels()) {
                 let sum = self.prometheus.getOrCreateSummary(withLabels: labels, forSummary: self)