<!-- Add the related story/sub-task/bug number, like Resolves#123, or
remove if NA -->
**Related issue:** Resolves#38889
Also delete the unnecessary logging.DiscardHandler and replace it with
slog.DiscardHandler
# Checklist for submitter
If some of the following don't apply, delete the relevant line.
- [x] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
- Changes file already present from previous PR
## Testing
- [x] Added/updated automated tests
- [x] QA'd all new/changed functionality manually
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Chores**
* Modernized internal logging infrastructure by transitioning from a
custom logging implementation to the standard library's structured
logging approach across multiple services and middleware components.
* **Refactor**
* Updated logging method signatures and error handling paths to use
standardized logging interfaces consistently throughout the platform
codebase.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->