Increase minimum supported rust version to 1.82

The zbus_macros -> proc-macro-crate -> indexmap dependency chain has
indexmap 2.12 which require 1.82 to compile.

It is not a dependency we can bypass. Have to bump MSRV to 1.82.

CI test updated.

Signed-off-by: Gris Ge <fge@redhat.com>