Update Dockerfile to use Python 3.10 instead of Python 3.8

[Inplex-sys]

Issue

The GNS3 server package requires Python >=3.9, but our Dockerfile was using the default Python 3.8.10 from Ubuntu Focal. This was causing build failures with the error:

ERROR: Package 'gns3-server-3.0.5.dev1' requires a different Python: 3.8.10 not in '>=3.9'

Changes

• Removed the installation of system Python packages (python3-pip, python3-all, etc.)
• Added build steps to compile and install Python 3.10.16 from source
• Set up pip for Python 3.10
• Updated all Python commands to explicitly use Python 3.10

Benefits

• Resolves the compatibility issue with GNS3 server requirements
• Provides a consistent Python environment across deployments

These changes allow the Docker image to build successfully and run the GNS3 server with the required Python version.

[grossmj]

Thanks for this. I have just one question though, why just not upgrade to use ubuntu:noble instead?

[Inplex-sys]

I choose to upgrade Python only to prevent any possible disruption to the overall environment. I didn't upgrade the base image to use Ubuntu Noble because it might involve possible compatibility issues with other dependencies or configurations.