[3.x.x] Add release workflow github action

[nan-li]

Description

One Line Summary

Action for building the release binaries and updating the Package.swift for a release

Details

Adapted from the workflow on main.

This action is intended to

1. build the binaries needed for an iOS release
2. Code sign the frameworks
3. Update the swift package
4. open a PR with the changes.

It does NOT

1. bump version numbers
2. write release notes
3. Create the Github Release after merging the pr
4. Distribute the Cocoapod

How to use this action:

1. Create a release branch with the bumped version numbers and push it.
2. Kick-off the action from the actions tab of the Github repo specifying the version number and release branch
3. Once the action has completed and created the PR write the release notes in the body of the PR and assign reviewers.

Motivation

Improve the release process

Manual testing

Released 3.12.10 with this action.

Affected code checklist

• Notifications
  • Display
  • Open
  • Push Processing
  • Confirm Deliveries
• Outcomes
• Sessions
• In-App Messaging
• REST API requests
• Public API changes

Checklist

Overview

• I have filled out all REQUIRED sections above
• PR does one thing
• Any Public API changes are explained in the PR details and conform to existing APIs

Testing

• I have included test coverage for these changes, or explained why they are not needed
• All automated tests pass, or I explained why that is not possible
• I have personally tested this on my device, or explained why that is not possible

Final pass

• Code is as readable as possible.
• I have reviewed this PR myself, ensuring it meets each checklist item

---

This change is