Parameter Validation Error when using get_parameter with a parameter set using ValueFrom

[inari-ldenton]

Overview

Currently if you attempt to generate a workflow with the following snippet you will get a validation error, this is occuring on hera version 5.1.0. I believe this is occurring due to the way the get_parameter function returns a Parameter. It will copy over the existing value_from field and set the value field for the task output. This leads to both value_from and value being set on the new parameter causing the validation to fail. In my testing, removing the value_from=obj.value_from, from the parameter being returned fixes the issue.

Example Code

from hera.workflows import DAG, Parameter, Task, Workflow, script
from hera.workflows.models import ValueFrom


@script(
    outputs=[
        Parameter(
            name="a",
            value_from=ValueFrom(path="/test_out"),
        )
    ]
)
def out():
    with open("/test_out", "w") as f_out:
        f_out.write("TESTEST")


@script()
def in_(a):
    print(a)


with Workflow(generate_name="script-param-passing-", entrypoint="d") as w:
    with DAG(name="d"):
        t1: Task = out()
        t2 = in_(arguments=t1.get_parameter("a"))
        t1 >> t2

# Write the workflow
with open("param_test.yaml", "w") as f_out:
    f_out.write(w.to_yaml())

Error

Traceback (most recent call last):
  File "**/param_passing.py", line 27, in <module>
    t2 = in_(arguments=t1.get_parameter("a"))
  File "**/lib/python3.10/site-packages/hera/workflows/task.py", line 185, in get_parameter
    return Parameter(
  File "pydantic/main.py", line 341, in pydantic.main.BaseModel.__init__
pydantic.error_wrappers.ValidationError: 1 validation error for Parameter
__root__
  Cannot specify both `value` and `value_from` when instantiating `Parameter` (type=value_error)