SDK-527: Prepare for Release 6.7.3

[github-actions]

Prepare for Release 6.7.3

SDK Release Checklist

• CHANGELOG.md updated with correct version
• Version numbers updated:
  • Iterable-iOS-SDK.podspec
  • Iterable-iOS-AppExtensions.podspec
  • sdkVersion in IterableAPI.swift
• README.md reviewed (if needed)
• All tests passing
• Documentation updated https://github.com/Iterable/iterable-docs/pull/1547

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 72.18%. Comparing base (1d93c6b) to head (b771820).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1076      +/-   ##
==========================================
+ Coverage   72.14%   72.18%   +0.04%     
==========================================
  Files         114      114              
  Lines        9538     9538              
==========================================
+ Hits         6881     6885       +4     
+ Misses       2657     2653       -4     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[franco-zalamena-iterable]

Missing changelog entries from merged PRs