Fix/ensure data can be ingested

[johann-r-unity]

Select the type of change:

• Small Changes - Typos, formatting, slight revisions
• New Content - New features, sections, pages, tutorials
• Site and Tools - Updates, maintenance, and new packages for the site and Docusaurus

Purpose of the Pull Request:
The OptanonWrapper() function is defined twice,
once in the head (https://github.com/Unity-Technologies/com.unity.multiplayer.docs/blob/main/config/scripts.config.js)
and
once in the footer https://github.com/Unity-Technologies/com.unity.multiplayer.docs/blob/bed5b1f3995322407a0d9986bebef8c93986a9e7/src/theme/Footer/index.js
This redefinition of the function causes an issue in our data ingestion pipelines that prevents the page viewed from being accessible in the analytics.
This PR removes this second occurrence which should it turn solve this issue.

Extra context
Initial problem discussion ; https://unity.slack.com/archives/C06PNK5M0MT/p1734715219397079
Resolution discussion ; https://unity.slack.com/archives/C036K4KH963/p1745875133962669

[jabbacakes]

I am not remotely qualified to approve this PR, so don't wait on my review. Happy for it to merge once someone qualified has looked at it 🙏

[anilopez]

Looks good to me.
Thanks