No need to store secrets for more than one matrix server.

Element uses a statically configured list of homeservers with disabled
presence. Without hosting our own Element this makes for pretty poor UI.

This reverts commit 82ac30f9.

Bump the mem settings higher again, now that we know they're not the
cause. Also increase the maximum connection count.

Less work_mem because this explodes easily. It's per-operation, which a
query can have multiple of, and also across multiple worker threads.

More shared_buffers and effective_cache_size as these are global.

Not sure if this is relevant, but postfix only listens on IPv4. This is
what I just tested as working, so keep it this way.

It's per worker, and we have 5 of them.

This reverts commit 8e4eac7d.

Revert this feature as its part of a keycloak change that must go
through review via a merge request.

This reverts commit cadfd2c5.

Revert this feature as its part of a keycloak change that must go
through review via a merge request.

This reverts commit 5446a3d0.

Revert this feature as its part of a keycloak change that must go
through review via a merge request.

Add federation_reader as a another worker.