Add Prometheus Provider

### Description

Prometheus supports a pushGateway option to push metrics to Prometheus.
This might be useful in cases where metrics needs to be pushed in the ETL stage.

For example, BigQuery has metrics stored in information_schema tables which can be queried using Standard SQL. Its useful to run the Query and store the metrics in prometheus on a periodic basis.

https://github.com/m-lab/prometheus-bigquery-exporter

Suggestion is to add a Prometheus provider first and have a separate PR for BigQueryToPrometheus transfer feature.
### Use case/motivation

_No response_

### Related issues

_No response_

### Are you willing to submit a PR?

- [X] 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)

Review the proposed Prometheus provider and the PushGateway use case described in the issue, including the linked prometheus-bigquery-exporter example. Define the provider's scope separately from the proposed BigQueryToPrometheus transfer feature; done means the provider can push metrics to Prometheus through PushGateway.

Written by the indexing model from the issue text.