* Updating Python Requirements

* Fixing test failure.

* Update timezone count for new pytz version

Co-authored-by: Awais Qureshi <awais.qureshi@arbisoft.com>
Co-authored-by: usamasadiq <usama.sadiq@arbisoft.com>

* Pin requirements to temporarily fix instructor task registration

We ran into an issue where instructor tasks were not being registered with celery correctly, resulting in: https://openedx.atlassian.net/browse/CR-2982

The cause wasn’t clear, so we started reverting some recent, suspect PRs.  When we reverted #25746, the issue went away.

The revert PR was this one: https://github.com/edx/edx-platform/pull/25766

So that we can unpause our deployment pipelines, we’re temporarily pinning the versions of the four packages upgraded in #25746 so we can continue to investigate.

* Result of make upgrade, propagating constraints out to other requirements files

* bumping enterprise version

* adding pillow constraint

* updating usage of EnterpriseCustomerBrandingConfiguration

ENT-3442

We introduce a new documentation target, where we use the featuretoggles
Sphinx extension from code-annotations to generate human-readable
documentation of feature toggles in edx-platform. The annotation report
is generated on-the-fly based on the standard feature toggle
configuration file in code-annotations.

In addition, we add new doc.in & doc.txt requirement files that will be
pip-installed by readthedocs to generate the documentation targets.