Update README.md (#3688)

README.md

@@ -118,7 +118,7 @@ Once you have your Swift package set up, adding Alamofire as a dependency is as
 
 ```swift
 dependencies: [
-    .package(url: "https://github.com/Alamofire/Alamofire.git", .upToNextMajor(from: "5.6.1"))
+    .package(url: "https://github.com/Alamofire/Alamofire.git", .upToNextMajor(from: "5.6.4"))
 ]
 ```