RUM-5650 chore: Refine Smoke Tests and add Swift 5.9 coverage

[ncreated]

What and why?

📦 This PR reorganizes and improves the coverage of smoke tests for our iOS SDK. It now includes coverage for all supported Swift versions while maintaining compatibility with various dependency managers.

How?

The smoke-test stage has been streamlined to 4 key jobs:

• Smoke Test (iOS) and Smoke Test (tvOS): These jobs test SDK integration through CocoaPods, Carthage, Xcode's SPM, and XCFrameworks. They run on a macos:sonoma runner with Xcode 15.4.

• SPM Build (Swift 5.9): This job builds Package.swift for each supported platform using the macos:ventura runner with Xcode 15.2.

• SPM Build (Swift 5.10): Similar to the above, but for Swift 5.10 using the macos:sonoma runner with Xcode 15.4.

The two "SPM Build" jobs now fully mirror SDK builds in Swift Package Index.

Review checklist

• [ ] Feature or bugfix MUST have appropriate tests (unit, integration)
• [ ] Make sure each commit and the PR mention the Issue number or JIRA reference
• [ ] Add CHANGELOG entry for user facing changes

[datadog-datadog-prod-us1[bot]]

Datadog Report

Branch report: ncreated/RUM-5650/enhance-smoke-testing-on-ci Commit report: 9e4cc5f Test service: dd-sdk-ios

:white_check_mark: 0 Failed, 3479 Passed, 0 Skipped, 2m 23.51s Total Time :small_red_triangle_down: Test Sessions change in coverage: 5 decreased, 2 increased, 7 no change

:small_red_triangle_down: Code Coverage Decreases vs Default Branch (5)

• test DatadogInternalTests iOS 79.44% (-0.04%) - Details
• test DatadogTraceTests tvOS 54.29% (-0.03%) - Details
• test DatadogInternalTests tvOS 79.52% (-0.03%) - Details
• test DatadogTraceTests iOS 54.25% (-0.02%) - Details
• test DatadogSessionReplayTests iOS 30.6% (-0.02%) - Details