Adds a note in the `podman machine info` manpage that clarifies
that `defaultmachine` in the `podman machine info` output does
not suggest that a user can set a default podman machine via
system connections.
Additionally adds a Podman 6.0 TODO comment to change the name of the
field to `ActiveMachineConnection` to better describe its purpose.
[NO NEW TESTS NEEDED]
Signed-off-by: Jake Correnti <jakecorrenti+github@proton.me>
8eb7eff899