Update to Matrix 1.71.0

[e1mo]

This has not been tested on dev yet. Due to the python3.7 requirement introduced in v1.50 an upgrade on our dev host (Ubuntu 18.04 LTS, python 3.6) requires more time than I have right now. However, prod is running on Debian 10 / python 3.7 that is fine. I would strongly prefer testing this before rolling the update out to production. However, after reading the upgrade notes I do not see any significant difficulties coming. Depending on how you see it, I think we could give directly going to production a try (Of course doing proper procedure with backups before hand and making synapse unreachable until we are assured that nothing obvious broke).

From reading the change log / upgrade notes, those changes seem as if they could affect us (but in the end don't).

• v1.64.0
  - Deprecation of the ability to delegate e-mail verification to identity servers: Should not affect us (I think) due to our usage of SSO
• v1.60.0
  - Possibility for failing migrations if the database is corrupted and has duplicates: We should be fine since we don't appear to have any dupes (on prod, not tested on dev):

SELECT COUNT(1) from ( SELECT state_group, prev_state_group FROM state_group_edges GROUP BY state_group, prev_state_group HAVING COUNT(ctid) > 1 ) AS dupes;
 count
-------
     0
(1 row)

• v1.50
  - Python 3.7 and PostgresQL 10+ requirement: Fine in prod, dev runns on Python 3.6

[n0emis]

This will break with 1.64, you'd also have to remove account_threepid_delegates from the synapse config

[n0emis]

Please update the synapse role to n0emis/ansible-role-synapse@147d40f (see my comment above)