Impish Indri is now open for development

[Matthias Klose]

We’re pleased to announce that impish is now *open for development*.
auto-sync has been enabled and will run soon. As usual, we expect a
large influx of builds and autopkgtests in this initial period, which
will cause delays. Please help with fixing any breakage that occurs.

The release schedule can be found at

  https://discourse.ubuntu.com/t/impish-indri-release-schedule/18540

A major change this cycle will be the GCC defaults change to GCC 11 planned for
July, introducing C++17 by default.

Matthias