chore: Logging Plugin - WordPress 6.9 Compatibility

[colinmurphy]

Overview

We need to ensure that the plugin is compatible with WordPress 6.9

Criteria

• Manual testing of the plugin with WordPress 6.9
• Update the readme.txt to include "Tested up to: 6.9"
• Update test suite to set 6.9 as default and include 6.9 for automated tests

[josephfusco]

PR: #531

[josephfusco]

This is also being tracked here #439

[ahuseyn]

Merged: #531