There's a merged pull request on the void-packages repository

synapse: update to 1.49.0.
https://github.com/void-linux/void-packages/pull/34531

Description:
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Remove outdated INSTALL and include default configs in package instead

Remove unneeded `finish` script from `synapse` service

Use `synapse_homeserver` entrypoint instead of calling python directly

Redirect stderr to stdout so that errors with config can be seen by user

Support ${makejobs} in do_check()