Fix version

Author: abnegate

README.md

@@ -31,7 +31,7 @@ Add the package to your `Package.swift` dependencies:
 
 ```swift
     dependencies: [
-        .package(url: "git@github.com:appwrite/sdk-for-apple.git", from: "12.0.0"),
+        .package(url: "git@github.com:appwrite/sdk-for-apple.git", from: "12.1.0"),
     ],
 ```
 

Sources/Appwrite/Client.swift

@@ -23,7 +23,7 @@ open class Client {
         "x-sdk-name": "Apple",
         "x-sdk-platform": "client",
         "x-sdk-language": "apple",
-        "x-sdk-version": "12.0.0",
+        "x-sdk-version": "12.1.0",
         "x-appwrite-response-format": "1.8.0"
     ]