Use benjaminrodenberg/fenics for CI stage "Build and Test"

[BenjaminRodenberg]

The image quay.io/fenicsproject/stable:current triggers the following error in our tests:

[DEPRECATION NOTICE] Docker Image Format v1 and Docker Image manifest version 2, schema 1 support is disabled by default and will be removed in an upcoming release. Suggest the author of quay.io/fenicsproject/stable:current to upgrade the image to the OCI Format or Docker Image manifest v2, schema 2. More information at https://docs.docker.com/go/deprecated-image-specs/

I, therefore, created my own image based on a fenics installation with apt.