Upgrade the Gitaly server version to f87bc1e98 (Merge branch
'pks-create-repository-atomic' into 'master', 2021-11-24), which
introduces a feature flag into Gitaly's code base changing the semantics
of CreateRepository and related RPCs to create repositories atomically.
This both implements proper voting on created repositories in Gitaly
Cluster setups, and causes these RPCs to fail in case the target
repository exists already.

This reverts commit 73c3684e.

To remedy ERROR: syntax error at or near "MATERIALIZED" because
some system is still using PG11.

In f80312d8c (repository: Remove deprecated and unused fields from
GetRawChanges, 2021-11-11), Gitaly removed some deprecated fields from
the RawChanges RPC. As it turned out, these fields were still used by
the Elasticsearch indexer, whose tests subsequently broke. The change
was thus reverted via b17e6c876 (Revert "repository: Remove deprecated
and unused fields from GetRawChanges", 2021-11-16).

Upgrade the Gitaly server version to include this change to fix the
incompatibility.