refactor(perf): Use first instead of filter

Reduces benchmark `graphql` time by 4%

Author: NeedleInAJayStack

Sources/GraphQL/Execution/Execute.swift

@@ -1057,10 +1057,7 @@ func defaultResolve(
     }
 
     let mirror = Mirror(reflecting: source)
-    guard let value = mirror.getValue(named: info.fieldName) else {
-        return nil
-    }
-    return value
+    return mirror.getValue(named: info.fieldName)
 }
 
 /**

Sources/GraphQL/SwiftUtilities/Mirror.swift

@@ -16,7 +16,7 @@ func unwrap(_ value: any Sendable) -> (any Sendable)? {
 
 extension Mirror {
     func getValue(named key: String) -> (any Sendable)? {
-        guard let matched = children.filter({ $0.label == key }).first else {
+        guard let matched = children.first(where: { $0.label == key }) else {
             return nil
         }