fix(python-builder): [part 1] Replace continuumio/miniconda3 with condaforge/miniforge3 + upgrade to Python 3.12

[tyndria]

What

Summary of changes

• Upgraded python, miniforge and poetry to support Python 3.12
• Replaced default channel image with the community-managed image.
• Remove explicit git installation as it's already a part of the used image

Checklist

• Added/updated unit tests
• Added/updated documentation
• Checked for typos in variable names, comments, etc.
• Added licences for new files

Testing

• Run lint command in the updated container ✅
• Run tests from /python folder in the updated container ✅
• Pushed python package to the pypi test index from the python-builder container - ✅

Next steps

• Push the new image (seldonio/python-builder:0.9 tag) to the seldonio hub, after push CI won't fail

[tyndria]

This is for testing purposes only (to test workflow after we push the image)

[tyndria]

For testing purposes only (revert)