Dependency management with a stored_as_script storage backend

[sm-Fifteen]

I have a number of machines I can't install Docker on that I would like to use as agents for my prefect setup. I'm using a git (Bitbucket) storage backend and just realized that none of the stored_as_script storage backends appear to have any way to handle dependencies. Even something really simple:

# shared/tasks/oracle.py
import cx_Oracle

class OracleFetch(Task):
    def __init__(user, password, dsn, query, commit):
        pass

    @defaults_from_attrs("query", "commit")
    def run(query, commit):
        pass

######################
# flows/test-flow.py
from prefect import Flow
from prefect.storage import Local, Bitbucket
from prefect.tasks.secrets import PrefectSecret
from shared.tasks.oracle import OracleFetch


script_storage_location = Bitbucket(...)

with Flow("OracleTest", storage=script_storage_location) as flow:
    password = PrefectSecret("DB_PASS")
    data = OracleFetch("admin", password, "//myoracle/myservice", "select sysdate from dual;")

Even if I happen to have cx_Oracle installed on all my agents (which is easy to forget), Bitbucket storage only fetches the actual file the flow is defined in, so the OracleFetch task I'm defining in this shared.tasks.oracle module is not going to be available unless I have --import-path set as a launch option on all my agents and then separately make sure to keep that separate module (which I happen to keep in the same git repository, though it could also be a git submodule) up to date in case I make any changes to it. If I need to install all the pip dependencies and keep those up to date as well, that's an extra layer of maintenance on top.

The Docker storage backend already lets you specify additional files to include and python_dependencies to preload, so it doesn't have that issue.

Besides copy-pasting those shared tasks in any flow that might need them or getting them upstreamed, is there any way to currently manage the runtime dependencies of a flow in Prefect without using Docker?

EDIT: I get the feeling issues #3513 and #3859 are among the missing parts of the documentation that would be helpful, here.

EDIT2: See also #4175