Use ecflow python API to set events for post jobs

[RussellManser-NCO]

In the next implementation, we should use the ecflow python API to set events to trigger post jobs in grib2writer.py (see #53). This will require ecflow to be built with python 3.12 and (likely) included in the venv.

The solution proposed in #53 was

# import statements
# ...

import ecflow

# ...

        # Release post job to create index files and copy files to COM
        if os.getenv("envir") is not None:
            client = ecflow.Client(
                host=os.getenv("ECF_HOST"),
                port=os.getenv("ECF_PORT"),
            )
            ECF_NAME = os.getenv("ECF_NAME")
            client.force_event(f"{ECF_NAME}:release_f${lead:03d}", "set")