Upgrade Debian to Bullseye

[J0WI]

Buster is the most recent version. Please also consider the buster-slim variant. buildpack-deps is too much overhead for a simple image like this.

[russorat]

@J0WI thanks for opening this. We will take a look.

[J0WI]

I've created #380

[J0WI]

Meanwhile Bullseye is the current version.

[powersj]

This is done for Telegraf images, TBD for other images.

[J0WI]

Debian Stretch is now EOL

[powersj]

@bnpfeife I think Kapacitor 1.6 is the only supported image that still uses stretch. Maybe InfluxDB 1.7?

[J0WI]

Kapacitor 1.5 is still listed in https://github.com/docker-library/official-images/blob/master/library/chronograf