Add receive_ephemeral everywhere de.sorunome.msc2409.push_ephemeral is used

Ref:

- 33f3ccd6ae/CHANGELOG.md (L134-L136)
- 7165d3fa58/appservice/registration.go (L30)

Intentionally not removing the old configuration setting yet, as some bridges may/do not support
the new setting name. It's likely just bridgev2 mautrix bridges that have been updated and support both right now.

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

@@ -32,5 +32,6 @@ rate_limited: false
 {% if matrix_hookshot_encryption_enabled %}
 de.sorunome.msc2409.push_ephemeral: true
 push_ephemeral: true
+receive_ephemeral: true
 org.matrix.msc3202: true
 {% endif %}