Remove support for PostgreSQL 13 (#19170)

This PR removes support for PostgreSQL 13 as it is deprecated
(tomorrow).
Uses https://github.com/element-hq/synapse/pull/18034 as a reference of
where to look, and also found a few other places that needed updating.
I didn't see anywhere in Complement that needs updating.
There is a companion Sytest PR deprecating psql13 over there:
https://github.com/matrix-org/sytest/pull/1418

### Pull Request Checklist

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* [X] Pull request is based on the develop branch
* [X] Pull request includes a [changelog
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- Be a short description of your change which makes sense to users.
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instead of "Moved X method from `EventStore` to `EventWorkerStore`.".
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[linters](https://element-hq.github.io/synapse/latest/development/contributing_guide.html#run-the-linters))

docker/complement/Dockerfile

@@ -11,7 +11,7 @@ ARG SYNAPSE_VERSION=latest
 ARG FROM=matrixdotorg/synapse-workers:$SYNAPSE_VERSION
 ARG DEBIAN_VERSION=trixie
 
-FROM docker.io/library/postgres:13-${DEBIAN_VERSION} AS postgres_base
+FROM docker.io/library/postgres:14-${DEBIAN_VERSION} AS postgres_base
 
 FROM $FROM
 # First of all, we copy postgres server from the official postgres image,
@@ -26,7 +26,7 @@ RUN adduser --system --uid 999 postgres --home /var/lib/postgresql
 COPY --from=postgres_base /usr/lib/postgresql /usr/lib/postgresql
 COPY --from=postgres_base /usr/share/postgresql /usr/share/postgresql
 COPY --from=postgres_base --chown=postgres /var/run/postgresql /var/run/postgresql
-ENV PATH="${PATH}:/usr/lib/postgresql/13/bin"
+ENV PATH="${PATH}:/usr/lib/postgresql/14/bin"
 ENV PGDATA=/var/lib/postgresql/data
 
 # We also initialize the database at build time, rather than runtime, so that it's faster to spin up the image.