Add some missing tags to Synapse role

Without these:

- `--tags=install-synapse` and `--tags=install-all` would be incomplete
and will not contain Synapse worker configuration

- `--tags=install-synapse-reverse-proxy-companion` and
  `--tags=setup-synapse-reverse-proxy-companion` would not contain
  Synapse worker configuration

roles/custom/matrix-synapse/tasks/main.yml

@@ -6,6 +6,10 @@
   tags:
     - setup-all
     - setup-synapse
+    - install-all
+    - install-synapse
+    - setup-synapse-reverse-proxy-companion
+    - install-synapse-reverse-proxy-companion
     - start
     - start-all
     - start-group