fix_assert_model_version

[venkatram-dev]

Description

Please include a summary of the change and which issue is fixed or implemented. Please also include relevant motivation and context (e.g. links, docs, tickets etc.).

Fixes this issue https://github.com/roboflow/roboflow-python/issues/314

Steps to reproduce

From the UI, Created a new project, new version with sample dataset, created version.

Ran the training code.

workspace = rf.workspace()

project = workspace.project('test2-forest-fire-detection')

version = project.version(6)

print ('version',version)

version.train()

Getting error

Traceback (most recent call last):
  File "/Users/venkat/Documents/robo_python_trial/r_train.py", line 13, in <module>
    version.train()
  File "/Users/venkat/Documents/robo_python_trial/rvenv/lib/python3.12/site-packages/roboflow/core/version.py", line 450, in train
    assert self.model
           ^^^^^^^^^^
AssertionError

List any dependencies that are required for this change.

Type of change

Please delete options that are not relevant.

• [ ] Bug fix (non-breaking change which fixes an issue)

How has this change been tested, please provide a testcase or example of how you tested the change?

Tested in my local

Any specific deployment considerations

For example, documentation changes, usability, usage/costs, secrets, etc.

Docs

• [ ] Docs updated? What were the changes: