Change flakies and nightlies so scheduled less often

Chris Thistlethwaite <christ@apache.org>
9:09 AM (25 minutes ago)
 to dev, team

Greetings!

During the Jenkins outage yesterday I noticed a ton of builds from
HBase-Flaky-Tests 
https://builds.apache.org/view/H-L/view/HBase/job/HBase-Flaky-Tests/ in
the queue. Turns out this runs a bunch of pipeline builds every hour
which clogs up Jenkins, both for you and other projects. For example,
branch-2.0 is currently queuing 3 builds, waiting on the 4th to finish,
and it's also behind the HBase Nightly.

That brings me to HBase Nightly 
https://builds.apache.org/view/H-L/view/HBase/job/HBase%20Nightly/ it
runs every 6 hours, which is a bit excessive for a nightly build which
by definition should be once a day. Especially as it gets dangerously
close to running into itself as builds currently around 4-5 hours of
build time.

I suggest something more like Flaky-Tests every 6 hours and the Nightly
once a day. If you agree to these changes, feel free to update Jenkins.
Otherwise, I'll update the jobs in the next few days if there is no
response.

Please add team@infra.apache.org and/or my address to any replies as
we're not subbed to your dev list.

Thank you,
Chris T.