[PATCH] ci: drop Travis configuration

[Aaron Conole]

David Marchand <david.marchand at redhat.com> writes:

> We stopped using Travis in the main branch and in the public CI in favor
> of GHA more than a year ago.
> The UNH community lab now covers testing native compilation and unit
> tests for ARM platforms.
>
> We decided to stop maintaining the configuration in our repository with
> the argument that "if it is not tested, it is broken".
>
> Signed-off-by: David Marchand <david.marchand at redhat.com>
> ---

Acked-by: Aaron Conole <aconole at redhat.com>