hookshot: Allow the localpart of the hookshot-bot to be defined (#3853)

* set localpart of hookshot bot in main.yml

* set sender_localpart in registration.yml.j2 template to variable

* prettier location for bot localpart in main.yml

* Update main.yml

* Update registration.yml.j2

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Co-authored-by: Slavi Pantaleev <slavi@devture.com>

roles/custom/matrix-bridge-hookshot/templates/registration.yml.j2

@@ -25,7 +25,7 @@ namespaces:
     - regex: "#github_.+:{{ matrix_domain }}"
       exclusive: true
 
-sender_localpart: hookshot
+sender_localpart: {{ matrix_hookshot_bot_localpart | to_json }}
 url: "http://{{ matrix_hookshot_container_url }}:{{ matrix_hookshot_appservice_port }}" # This should match the bridge.port in your config file
 rate_limited: false