Added config template field to EmrServerlessStartJobOperator

[mahammi]

Added config template field to EmrServerlessStartJobOperator, as requested in issue #31711.

[boring-cyborg]

Congratulations on your first Pull Request and welcome to the Apache Airflow community! If you have any issues or are unsure about any anything please check our Contribution Guide (https://github.com/apache/airflow/blob/main/CONTRIBUTING.rst)
Here are some useful points:

• Pay attention to the quality of your code (ruff, mypy and type annotations). Our pre-commits will help you with that.
• In case of a new feature add useful documentation (in docstrings or in docs/ directory). Adding a new operator? Check this short guide Consider adding an example DAG that shows how users should use it.
• Consider using Breeze environment for testing locally, it's a heavy docker but it ships with a working Airflow and a lot of integrations.
• Be patient and persistent. It might take some time to get a review or get the final approval from Committers.
• Please follow ASF Code of Conduct for all communication including (but not limited to) comments on Pull Requests, Mailing list and Slack.
• Be sure to read the Airflow Coding style.
  Apache Airflow is a community-driven project and together we are making it better 🚀.
  In case of doubts contact the developers at:
  Mailing List: dev@airflow.apache.org
  Slack: https://s.apache.org/airflow-slack

[o-nikolas]

Can you add the template_fields_renderers attribute and specify json for this new field? That way it will render nicely in the UI. You can also add the same for configuration_overrides while you're at it 😄
(docs and example of setting the renderers)

[ferruzzi]

Still LGTM :P :P

[boring-cyborg]

Awesome work, congrats on your first merged pull request! You are invited to check our Issue Tracker for additional contributions.

[o-nikolas]

Congrats on your first merged PR @mahammi!

[taehoka]

Is it possible to use jinja on config field?
I tested this with apache-airflow-providers-amazon==8.6.0, but it seems jinja is not working.

If it is due to renderer type, is there alternative solutions?
I just want to put execution date on EMR serverless's job name.