fix(cocoapods): prevent mixed SDK component versions

[thomson-t]

Background

A pinned mParticle Apple SDK version could still resolve a newer
mParticle-Apple-SDK-Swift pod because the ObjC podspec did not specify
a version constraint. This could install incompatible core SDK components.

What Has Changed

• Pin mParticle-Apple-SDK-Swift to the same version as
  mParticle-Apple-SDK-ObjC.
• Keep SwiftPM unchanged because its internal Swift and Objective-C targets
  already come from the same pinned package tag.
• Keep the release workflow unchanged because it already updates all core
  podspec versions together and publishes them in dependency order.

Screenshots/Video

N/A — no visual changes.

Checklist

• Self-review completed
• Tests added or updated
• Tested locally

[cursor]

PR Summary

Low Risk
Single podspec dependency constraint change with no runtime or API changes; reduces version-mismatch risk for CocoaPods installs.

Overview
CocoaPods consumers of mParticle-Apple-SDK-ObjC could previously pull a newer mParticle-Apple-SDK-Swift than the pinned ObjC release because the dependency had no version constraint.

The ObjC podspec now declares mParticle-Apple-SDK-Swift with s.version.to_s, so both core pods resolve to the same release. SwiftPM and the existing release workflow are unchanged.

^{Reviewed by Cursor Bugbot for commit 4921ef8. Bugbot is set up for automated code reviews on this repo. Configure here.}

[github-actions]

📦 SDK Size Impact Report

Measures how much the SDK adds to an app's size (with-SDK minus without-SDK).

Metric	Target Branch	This PR	Change
App Bundle Impact	1.79 MB	1.79 MB	+N/A
Executable Impact	848 bytes	848 bytes	+N/A
XCFramework Size	6.49 MB	6.48 MB	-8 KB

➡️ SDK size impact change is minimal.

Raw measurements

Target branch (main):

{"baseline_app_size_kb":84,"baseline_executable_size_bytes":75464,"with_sdk_app_size_kb":1920,"with_sdk_executable_size_bytes":76312,"sdk_impact_kb":1836,"sdk_executable_impact_bytes":848,"xcframework_size_kb":6644}

This PR:

{"baseline_app_size_kb":84,"baseline_executable_size_bytes":75464,"with_sdk_app_size_kb":1920,"with_sdk_executable_size_bytes":76312,"sdk_impact_kb":1836,"sdk_executable_impact_bytes":848,"xcframework_size_kb":6636}