Update beeper-linkedin configuration to latest upstream config and properly pass double-puppeting login shared secrets

We used to pass the shared secret for double-puppeting via a
`login_shared_secret` parameter, which doesn't seem to exist anymore.
The proper way to do it is via `login_shared_secret_map`.

The comments for `login_shared_secret_map` seem to indicate that it's
only usable with the shared-secret-auth password provider.

However, this bridge is based on mautrix-python (`>=0.20.5,<0.21`) as
per its `requirements.txt`
Support for double-puppeting via arbitrary access tokens landed in
mautrix-python 0.20.1 (6f25b62e80/CHANGELOG.md (L44-L53)),
so it should be possible to use appservice double-puppet.
Related to af04ca1238

A bunch of other parameters seem to have moved around as well.

This patch introduces some new Ansible variables for controlling
additional settings related to encryption, etc.

roles/custom/matrix-bridge-beeper-linkedin/tasks/validate_config.yml

@@ -11,3 +11,12 @@
     - {'name': 'matrix_beeper_linkedin_homeserver_token', when: true}
     - {'name': 'matrix_beeper_linkedin_database_hostname', when: "{{ matrix_beeper_linkedin_database_engine == 'postgres' }}"}
     - {'name': 'matrix_beeper_linkedin_container_network', when: true}
+
+- name: (Deprecation) Catch and report renamed beeper-linkedin settings
+  ansible.builtin.fail:
+    msg: >-
+      Your configuration contains a variable, which now has a different name.
+      Please change your configuration to rename the variable (`{{ item.old }}` -> `{{ item.new }}`).
+  when: "item.old in vars"
+  with_items:
+    - {'old': 'matrix_beeper_linkedin_login_shared_secret', 'new': '<superseded by matrix_beeper_linkedin_bridge_login_shared_secret_map_*>'}