Attempt staticlib

[neekolas]

Summary

This PR updates our swift bindings from dynamic lib (.dylib) to static lib (.a) files.

We're also adding a GitHub action that publishes swift bindings with the following directory structure to a Release artifact:

test-swift-bindings-ecb15b7/LibXMTPSwiftFFI.zip contents

├── LICENSE
├── LibXMTPRust.xcframework
│   ├── Info.plist
│   ├── ios-arm64
│   │   ├── Headers
│   │   │   ├── module.modulemap
│   │   │   └── xmtpv3FFI.h
│   │   └── libxmtpv3.a
│   ├── ios-arm64-simulator
│   │   ├── Headers
│   │   │   ├── module.modulemap
│   │   │   └── xmtpv3FFI.h
│   │   └── libxmtpv3.a
│   └── macos-arm64
│       ├── Headers
│       │   ├── module.modulemap
│       │   └── xmtpv3FFI.h
│       └── libxmtpv3.a
└── Sources
    └── LibXMTP
        └── xmtpv3.swift

A demo of the released artifact can be seen here: https://github.com/xmtp/libxmtp/releases/tag/test-swift-bindings-ecb15b7

The release artifact zip folder will be referenced from our libxmtp-swift repository so that it can simulatenously publish to Swift Package Manager, and Cocoapods.

Before this PR is merged, we would like to validate the setup against xmtp-ios and xmtp-react-native repos. This testing can be done via the following three PRs:

• libxmtp-swift: Updated to static libs, added remote binary url libxmtp-swift#4
• xmtp-ios: Access libxmtp-swift with static binaries xmtp-ios#225
• xmtp-react-native: Import static libxmtp libraries from libxmtp-swift podspec update xmtp-react-native#229