fix: submodules drivers load for custom napalm packages

[leoparente]

This pull request includes several changes to enhance the discovery of NAPALM drivers and improve the testing framework. The most important changes include the addition of a new function to walk through NAPALM packages, modifications to the napalm_driver_list function, and updates to the test cases to ensure comprehensive coverage.

Enhancements to NAPALM driver discovery:

• device-discovery/device_discovery/discovery.py: Added the walk_napalm_packages function to walk through directory trees and identify NAPALM network driver classes.
• device-discovery/device_discovery/discovery.py: Modified the napalm_driver_list function to use the new walk_napalm_packages function for discovering additional NAPALM drivers.

Dependency updates:

• device-discovery/pyproject.toml: Removed the importlib-metadata dependency as it is no longer needed.

Improvements to test cases:

• device-discovery/tests/test_discovery.py: Added new test cases to validate the functionality of the walk_napalm_packages function, including scenarios for successful discovery, no drivers found, and exception handling.
• device-discovery/tests/test_discovery.py: Updated existing test cases to mock the packages_distributions function and ensure compatibility with the new implementation. [1] [2]

[github-actions]

Coverage Report

File	Stmts	Miss	Cover	Missing
device_discovery
discovery.py	63	2	97%	142–145
main.py	32	2	94%	90, 96
server.py	68	4	94%	33–35, 128, 131
version.py	7	1	86%	14
device_discovery/policy
manager.py	41	2	95%	36–37
runner.py	66	1	98%	49
TOTAL	429	12	97%

Tests	Skipped	Failures	Errors	Time
54	0 💤	0 ❌	0 🔥	6.119s ⏱️

[github-actions]

🎉 This PR is included in version 0.4.2 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀

[github-actions]

🎉 This PR is included in version 0.1.2 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀