Setup proper pip package

[adeebshihadeh]

pandacan is already a pip package, but it doesn't include the FW and some other things to fully use the panda project.

The package should be sufficient to remove panda as a submodule from openpilot and add it as a normal Python dependency to the pyproject.toml. For validation, make an openpilot PR that does this and ensure CI passes.

[shreyanshjain7174]

@adeebshihadeh can I work on this one ?

[shreyanshjain7174]

Created PR #2241 to implement comprehensive pip package with all necessary components including firmware, certificates, and build tools. The package enables openpilot to replace git submodule usage with standard pip installation.

[shreyanshjain7174]

This PR converts the panda repository to be pip-installable so openpilot can use it as a normal
Python dependency instead of a git submodule.

Changes:

Add pyproject.toml package configuration
Add setup.py for pip compatibility
Export USBPACKET_MAX_SIZE constant needed by tests
The package installs as "panda" and maintains all existing import paths.