Run all tests by default
# What does this PR do?

This PR makes the default value for the crosstests PT<>TF and PT<>FLAX true by default. This way when a user runs tests locally, all tests are run (the only exception being the hub staging tests, which require setting an env variable anyway to use moon-staging instead of moon-landing). In the CI however each job runs the same tests as before since the env variables are set at False by default.
_The documentation is not available anymore as the PR was closed or merged._