Proposal: remove configobj dependency in favour of stdlib

[sshedi]

configobj is used in five places in cloud-init - all for basic key=value or INI parsing. None of its advanced features (comment round-tripping, interpolation, list values, nested sections) are actually used. Python's stdlib covers every use case here.

Removing it simplifies the dependency tree for every downstream distro that has to package and maintain it alongside cloud-init.

I have a working implementation with all existing tests passing. Happy to open a PR if this direction is welcome.

[holmanb]

If the solution works across the supported versions of Python, it sounds like this has potential.

[sshedi]

I will push the PR, let us see how it goes. Thanks for the prompt response.