Skip tests that depend on FAB when it's uninstalled

[Dev-iL]

(Issue created per request of @potiuk in #52648)

In the context of adding SQLA2 support, we'd like to enable the workflow that checks for SQLA2 compatibility ASAP, to help contributors avoid introducing regressions.

Currently, without upgrading to FAB5, the special SQLA2 workflow fails on some incompatibilities of airflow-core with FAB. To get it working, we should be able to add configurations to entrypoint_ci.sh to remove FAB (and perhaps other packages) and skip all the tests that depend on FAB.

Prerequisite: #46891
Related: #52233

[potiuk]

Cool. Thanks