[docs]: All cloud config examples

# Documentation request

There is a lot of unclarity around how the deb822 repo are handled.

Could we override the default /etc/apt/source.list.d/ubuntu.sources in Ubuntu Noble ?

There's briefly mentioned only here: https://cloudinit.readthedocs.io/en/latest/reference/yaml_examples/apt.html

but seems we still have to use sources_list and cannot specify extra sources in this format.

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*Reported from: https://cloudinit.readthedocs.io/en/latest/reference/examples.html*