support nose2 framework for jsnapy tests

[chidanandpujar]

Description of Issue/Question

Support nose2 framework for jsnapy unit tests

Setup

(Please provide relevant configs, xml snapshots and related files (Be sure to remove sensitive info).)

Steps to Reproduce Issue

(Include debug logs if possible and relevant. Error trace would be helpful too)
with python3.12.3 ,

https://github.com/Juniper/jsnapy/actions/runs/9030597104/job/24815206239?pr=411

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ERROR: tests.unit.test_snap (nose2.loader.ModuleImportFailure.tests.unit.test_snap)

ImportError: Failed to import test module: tests.unit.test_snap
Traceback (most recent call last):
File "/home/runner/work/jsnapy/jsnapy/venv/lib/python3.12/site-packages/nose2/plugins/loader/discovery.py", line 195, in _find_tests_in_file
module = util.module_from_name(module_name)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/runner/work/jsnapy/jsnapy/venv/lib/python3.12/site-packages/nose2/util.py", line 73, in module_from_name
import(name)
File "/home/runner/work/jsnapy/jsnapy/tests/unit/test_snap.py", line 10, in
from nose.plugins.attrib import attr
File "/home/runner/work/jsnapy/jsnapy/venv/lib/python3.12/site-packages/nose/init.py", line 1, in
from nose.core import collector, main, run, run_exit, runmodule
File "/home/runner/work/jsnapy/jsnapy/venv/lib/python3.12/site-packages/nose/core.py", line 12, in
from nose.loader import defaultTestLoader
File "/home/runner/work/jsnapy/jsnapy/venv/lib/python3.12/site-packages/nose/loader.py", line 21, in
from nose.importer import Importer, add_path, remove_path
File "/home/runner/work/jsnapy/jsnapy/venv/lib/python3.12/site-packages/nose/importer.py", line 12, in
from imp import find_module, load_module, acquire_lock, release_lock
ModuleNotFoundError: No module named 'imp'

Versions Report

(Provided by running jsnapy --version. Please also mention python version.)

JSNAPy version: 1.3.8.dev0