Rewrite Docker pipeline (#2404)

* Rewrite Docker pipeline

* Tweaks.

* Syntax fix

* Tidy

* yamllint

* actionlint

* Also push some images to ghcr.io

* Fix

* Syntax fix

* Fix username/token for dockerhub

* Tweaks.

* Fix cache type=

* Add dummy option for testing CI.

* Try fixing boolean

* Try strings...

* Try string Dockerfile

* Typo

* Try GITHUB_TOKEN

* quote string

* Fix.

* Get default Dockerfile if not running workflow dispatch

* Fix

* Typos

* Typo

* Make user enter this themselves (stops accidents).

* Typo

* Fix typo

* Try pushing non-user images to ghcr.io/fenics

* Fix.

* Make dev-env:nightly the same as MPICH

* Address Jorgen's comments.

Co-authored-by: Jørgen Schartum Dokken <[email protected]>