This commit adds support for LDAP authentication.
The Dockerfile has been modified to install the required Lua modules (lua-ldap) and the prosody.cfg.lua file has been modified to add environment variables for configuring the LDAP connection. These environment variables include LDAP_BASE, LDAP_SERVER, LDAP_ROOTDN, LDAP_PASSWORD, LDAP_FILTER, LDAP_SCOPE, LDAP_TLS, LDAP_MODE, and LDAP_ADMIN_FILTER.
The authentication variable has also been updated to use the value of the AUTHENTICATION environment variable, which defaults to "internal_hashed" if not set. This allows users to configure Prosody to use LDAP for authentication instead of the default internal hashing method.
* Update test dependencies: aioxmpp, pytest-asyncio + add pytz to requirements.txt
This fixes the following error when running the tests:
E ModuleNotFoundError: No module named 'pytz'
Instead of pytz only pytz-deprecation-shim was installed.
TODO Check if "pytz" can be removed from requirements.txt later on.
