Bump docker/build-push-action from 3 to 4 (#7)

Bump docker/setup-buildx-action from 1 to 2 (#5)

Bump docker/setup-qemu-action from 1 to 2 (#6)

Bump docker/build-push-action from 2 to 3 (#4)

Bump docker/login-action from 1 to 2 (#3)

Bump actions/checkout from 2 to 3 (#2)

Bump actions/github-script from 5 to 6 (#1)

Add dependabot config file

Import new apt repository key fingerprint

Update github actions badge

Upgrade to debian 11

Fix R apt repositories signing key

Remove unused readme

Build docker image from action

Remove microbadger layer badge