Add notice to notebook about running on linux

[boomermath]

Description

No code changes, just added a notice at the top of the notebook notifying users that this notebook can only be used on Linux due to rknn-toolkit2 only supporting Linux builds. Currently, we are recommending Google Colab and Kaggle as alternatives in case the user doesn't have access to a Linux system.

Meta

Merge checklist:

• Pull Request title is short, imperative summary of proposed changes
• The description documents the what and why
• If this PR changes behavior or adds a feature, user documentation is updated
• If this PR touches photon-serde, all messages have been regenerated and hashes have not changed unexpectedly
• If this PR touches configuration, this is backwards compatible with settings back to v2025.3.2
• If this PR touches pipeline settings or anything related to data exchange, the frontend typing is updated
• If this PR addresses a bug, a regression test for it is added

[boomermath]

This is pending testing on Kaggle to make sure it works there

[samfreund]

Also, kaggle testing.