Sometimes pull requests are merged during the week-end, triggering
a CI pipeline. Currently if such pipeline fails, the Avocado reports
are available for 2 days. For the reviewers working on the project
during office hours, the reports are already discarded when they
want to look at them. Increase this time to 1 week, which should
give reviewers enough time.

Only keep the reports on failure, which is the only case we'll
look at them.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Willian Rampazzo <willianr@redhat.com>
Message-Id: <20210525082556.4011380-8-f4bug@amsat.org>