Avocado venv bootstrap - deprecation/removal of eggs

[clebergnu]

Is your feature request related to a problem? Please describe.
Avocado is capable of deploying itself to other environments such as podman containers (and then be run by spawners other than process), it does so using Python eggs. Python eggs are deprecated and Avocado should not continue to rely on them.

Describe the solution you'd like
The standard way of deploying Python applications is now though PIP in isolated virtual environments (venvs). Avocado should attempt to do follow the standard.

To allow for offline operation in the deployed environments, Avocado should continue to be able to download the needed packages (currently it does eggs, but should also support wheels/tarballs).

If the filesystem is the same, or filesystem sharing is available, there could be a preparation of the venv (one for each platform/Python version) that would be given (preferably as read-only) to the deployed environment.

Describe alternatives you've considered
The alternative is dropping support for Avocado deployment when support for eggs are ultimately removed from the Python ecosystem. The downside would be more manual actions required for Avocado users to run tests in other environments.

[harvey0100]

- Design of possible solution

[PaulYuuu]

During the setup.py to pyproject.toml migration, this is also a blocker for fully deprecated the setup.py file.

Actually I am not the user of podman spawner and egg, so I am confusing if the container has network, why we cannot install wheels from pypi or from host?

Another solution I can think of is create an venv and install avocado in the venv, then copy the full venv dir to contianer, and container can directly use it.

After we addressed this issue, the following limitation(setuptools) should also be removed.

avocado/avocado/plugins/spawners/podman.py

Lines 235 to 252 in b6ac559

	# Setuptools
	# For now let's pin to setuptools 59.2.
	# TODO: Automatically get latest setuptools version.
	eggs = [
	f"https://github.com/avocado-framework/setuptools/releases/download/v59.2.0/setuptools-59.2.0-py{py_major}.{py_minor}.egg"
	]
	local_egg = self.config.get("spawner.podman.avocado_spawner_egg")
	if local_egg:
	eggs.append(local_egg)
	else:
	remote_egg = f"https://github.com/avocado-framework/avocado/releases/download/{VERSION}/avocado_framework-{VERSION}-py{py_major}.{py_minor}.egg"
	eggs.append(remote_egg)
	for url in eggs:
	path = self._fetch_asset(url)
	to = os.path.join("/tmp/", os.path.basename(path))
	result.append((path, to))
	return result

For publish wheel instead of egg in the avocado release, only avocado_framework-112.0-py3-none-any.whl, it supports all y stream python, and we will not have avocado_framework-112.0-py3.yy.egg