Update metrics publisher hostname when hostname is changed

[samfreund]

Description

When the hostname changes, the key of the metrics publisher will not be immediately updated. To fix this, we will check the key against the hostname and re-initialize the publisher if they do not match.

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 v2024.3.1
• 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
• Figure out a way to only extract models for the relevant hardware (ideally only pack the necessary models, but idk how viable that is since it necessitates a different JAR per)