Update doc version warning logic to exclude specific pages

[Victor-Boyd]

This commit modifies the Sphinx template logic to prevent the version warning message from appearing on the 'Contributing to ROS 2 Documentation' page and any pages within the 'Releases' section. The update is aimed at improving user experience by selectively displaying version warnings only where relevant.

Additionally, this change addresses and resolves issues #3949 and #3966, which were related to unwanted version warning messages on documentation pages deemed unnecessary for such alerts.

• Exclude '/Contributing/Contributing-To-ROS-2-Documentation.html' from version warning messages.
• Exclude any pages under '/Releases/' from version warning messages.
• Fixes #3949 and #3966.