feat: upversion to '4.0.0'

Author: runner

README.md

@@ -37,15 +37,15 @@ SolanaSwift is available through [CocoaPods](https://cocoapods.org). To install
 it, simply add the following line to your Podfile:
 
 ```ruby
-pod 'SolanaSwift', '~> 3.0.0'
+pod 'SolanaSwift', '~> 4.0.0'
 ```
 
 ### Swift package manager
 ```swift
 ...
 dependencies: [
     ...
-    .package(url: "https://github.com/p2p-org/solana-swift", from: "3.0.0")
+    .package(url: "https://github.com/p2p-org/solana-swift", from: "4.0.0")
 ],
 ...
 ```

SolanaSwift.podspec

@@ -8,7 +8,7 @@
 
 Pod::Spec.new do |s|
   s.name             = 'SolanaSwift'
-  s.version          = '3.0.0'
+  s.version          = '4.0.0'
   s.summary          = 'A client for Solana written in Swift.'
 
 # This description is used to generate tags and improve search results.