Seems like `default` is not a supported value and will not
make the bridge autoconfigure itself with the correct prefix anymore.

A value of `default` would be taken literally.

f9705b3323 reworked the configuration and missed wiring
these to the existing variables.

We'be already been going against upstream defaults and have been
enabling backfilling for a few other bridges (Messenger, Instagram, Telegram, Twitter).

Now I'm enabling backfilling by default for the remaining ones, for
consistency.

Related to:
- https://github.com/mautrix/gmessages/releases/tag/v0.5.0
- https://mau.fi/blog/2024-09-mautrix-release/

It seems like the new version does not support a `/metrics` endpoint.
We skip keep the Ansible variables, but they're not doing anything.

Related to:
- https://github.com/mautrix/meta/releases/tag/v0.4.0
- https://mau.fi/blog/2024-09-mautrix-release/

It seems like the new version does not support a `/metrics` endpoint.
We skip keep the Ansible variables, but they're not doing anything.

While working on upgrading the Meta bridges to bridgev2, I've noticed
that {% raw %} and {% endraw %} on lines like that (immediately
preceding `username_template` may cause YAML indentation issues.

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/3369

* fix synapse-admin image prefix

* fix typo

* switch to synapse-admin fork

* Fix typo

* Close unclosed ) and reword sentence

---------

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

Related to:

- https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/3518
- https://github.com/hifi/heisenbridge/issues/294

With this patch, when `matrix_heisenbridge_path_prefix` is the default
one we use (`/heisenbrdige`), URLs like this are constructed:

https://matrix.DOMAIN/heisenbridge/_heisenbridge/media/SERVER_NAME/MEDIA_ID/CHECKSUM/FILENAME

If `matrix_heisenbridge_path_prefix` is set to `/`, URLs like this are constructed:

https://matrix.DOMAIN/_heisenbridge/media/SERVER_NAME/MEDIA_ID/CHECKSUM/FILENAME

Our Traefik labels support handling both cases correctly.

`matrix_client_schildichat_docker_image` was adjusted to use the
Github Container Registry in 171f5f84a2cd058f0c53780, but the Renovate marker was not adjusted.

Related to: https://github.com/spantaleev/matrix-docker-ansible-deploy/pull/3485

Related to https://etke.cc/news/d3uw4utq4t3_rpxicrrfqqou_ynmptqjgk95pt-3n2s/

As reported in https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/3451#issuecomment-2331316593

Likely the solution to https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/3451

* postmoogle v0.9.21

* update postmoogle source code url

* update postmoogle renovate comment

Related to https://github.com/spantaleev/matrix-docker-ansible-deploy/issues/3479#issuecomment-2294956958

Shared Secret Auth double puppeting still works for this bridge, but
is deprecated and will go away in the future.

Shared Secret Auth double puppeting still works for this bridge, but
is deprecated and will go away in the future.

Shared Secret Auth double puppeting still works for this bridge, but
is deprecated and will go away in the future.

Shared Secret Auth double puppeting still works for this bridge, but
is deprecated and will go away in the future.

Shared Secret Auth double puppeting still works for this bridge, but
is deprecated and will go away in the future.

Shared Secret Auth double puppeting still works for this bridge, but
is deprecated and will go away in the future.

Shared Secret Auth double puppeting still works for these bridges, but
is deprecated and will go away in the future.

Shared Secret Auth double puppeting still works for this bridge, but
is deprecated and will go away in the future.

Since upgrading mautrix-slack (and pinning to v0.1.0) in e4b54c37fe258b17f49dd7ed58a18ef3abac1c41,
we expect double-puppeting to require the new appservice double-puppeting method.

This commit switches the mautrix-slack bridge to it.