Test image rebuild when cmake config changes

[dmnks]

We need a mechanism to rebuild the base test image in make check after a build dependency has been changed in the cmake configuration (see e.g. #3220). That, or just always reconfigure the local build in the test container before running the tests so that missing requirements are actually checked for.

Note that this is not needed in CI mode (make ci) since we always do a fresh cmake build there.