Include extra dependency groups 'systemd' and 'cache_memory' in debian packages

[anoadragon453]

Fixes #12631.

The systemd and cache_memory extra package groups contain python dependencies that are necessary for using all available options of the base distribution of Synapse in debian packages.

systemd provides the systemd-python package which is required for logging to the systemd journal, whereas cache_memory provides the pympler package, which is required for the caches.track_memory_usage homeserver config option.

These dependencies were available before the poetry changeover, where they seem to have gone missing. This PR adds these extras groups back.

Merging to the release-v1.58 branch with the intention of including this in a v1.58.1 release.

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I'm not sure if we also need to add the cache_memory extras group to the following line?

synapse/debian/build_virtualenv

Line 62 in 0d8d595

--extras="all,systemd,test" \

[richvdh]

I can't help but wonder if this is the right fix, or if we should go back to having all include, well, all the extras. (Or, most of them.)

(this used to be included via this code and this code).

[anoadragon453]

That is a good point. As it stands, the docker images also don't look to include pympler:

synapse/docker/Dockerfile

Line 64 in e5a76ec

RUN /root/.local/bin/poetry export --extras all -o /synapse/requirements.txt

[anoadragon453]

I'm assuming that dependencies for an experimental config option (cache.track_memory_usage) are in fact something that we'd like to include in Debian and Docker images, as they would allow people using those distribution methods to actually test the option.

In that case, including them in all sounds sensible.

I'm not sure if this was clear during the poetry switch, as they seem to have been purposely omitted during the switch:

synapse/pyproject.toml

Lines 236 to 239 in cc76560

	# omitted:
	# - cache_memory: this is an experimental option
	# - test: it's useful to have this separate from dev deps in the olddeps job
	# - systemd: this is a system-based requirement

[anoadragon453]

I'm going to push this PR through and get 1.58.1 out as that's preventing some .deb installations from starting, if that sounds sensible? Then we can look at clearing up this situation, and allowing testing of the experimental config option on docker.

[richvdh]

sgtm

[DMRobertson]

I can't help but wonder if this is the right fix, or if we should go back to having all include, well, all the extras. (Or, most of them.)

(this used to be included via this code and this code).

By my reading, the first link explicitly excludes systemd from all. I can't remember why I didn't include pympler; maybe just an oversight.

[richvdh]

lgtm othet than the changelog