Metrics task.cpu_usage and task.mem_usage are missing

### What do you see as an issue?

The docs define task cpu and memory usage but these metrics are missing in the latest release. I confirmed there were there in the latest 2.10.

https://airflow.apache.org/docs/apache-airflow/stable/administration-and-deployment/logging-monitoring/metrics.html#gauges

### Solving the problem

_No response_

### Anything else

_No response_

### Are you willing to submit PR?

- [ ] Yes I am willing to submit a PR!

### Code of Conduct

- [x] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

Start with the linked gauges documentation and compare the latest release with Airflow 2.10 to confirm when task.cpu_usage and task.mem_usage disappeared. Locate where these metrics are defined or emitted, then verify that the metrics are restored and the documentation matches the released behavior.

Written by the indexing model from the issue text.