Revert the libdgal mod once pyogrio fully supports Python 3.14.

[chalmerlowe]

Due to an issue with pyogrio (a dependency of geopandas) not fully supporting Python 3.14 yet, the pip install process for pyogrio fails which has a side effect of not installing libdgal-dev and several other dependencies.

Because libdgal is required for some of the tests in python-bigquery, we introduce this change to temporarily ensure that libdgal is available in the docker container. See here for the error message and additional details.

Once pyogrio fully supports Python 3.14, this update will no longer be needed and this change can/and should be removed. See here for status of the expected release for pyogrio that should introduce Python 3.14 support.

[chalmerlowe]

It looks like support for Python 3.14 has been added, per the release notes:
https://github.com/geopandas/pyogrio/releases

• Action: confirm that we can install without our change, if YES, revert.