Partially reverts #16796
This is causing errors of the form:
```
Error: Failed to CreateArtifact: Received non-retryable error: Failed request: (409) Conflict: an artifact with this name already exists on the workflow run
```
for the debs and wheels stages.
There were breaking changes that weren't included in the dependabot
changelog (:/):
https://github.com/actions/upload-artifact#breaking-changes
<!--
Fixes: # <!-- -->
<!--
Supersedes: # <!-- -->
<!--
Follows: # <!-- -->
<!--
Part of: # <!-- -->
Base: `release-v1.100` <!-- git-stack-base-branch:release-v1.100 -->
<!--
This pull request is commit-by-commit review friendly. <!-- -->
<!--
This pull request is intended for commit-by-commit review. <!-- -->
Original commit schedule, with full messages:
<ol>
<li>
Downgrade the `upload-artifact` and `download-artifact` actions to v3
</li>
</ol>
---------
Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>
During the migration the automated script to update the copyright
headers accidentally got rid of some of the existing copyright lines.
Reinstate them.
Pulled out of #16803 since the drive-by cleanup was maybe not as
drive-by as I had hoped.
<!--
Fixes: # <!-- -->
<!--
Supersedes: # <!-- -->
<!--
Follows: # <!-- -->
<!--
Part of: # <!-- -->
Base: `develop` <!-- git-stack-base-branch:develop -->
<!--
This pull request is commit-by-commit review friendly. <!-- -->
<!--
This pull request is intended for commit-by-commit review. <!-- -->
Original commit schedule, with full messages:
<ol>
<li>
Add a --generate-only option
</li>
</ol>
---------
Signed-off-by: Olivier Wilkinson (reivilibre) <oliverw@matrix.org>
Prior to this PR, if a request to create a public (public as in
published to the rooms directory) room violated the room list
publication rules set in the
[config](https://matrix-org.github.io/synapse/latest/usage/configuration/config_documentation.html#room_list_publication_rules),
the request to create the room was denied and the room was not created.
This PR changes the behavior such that when a request to create a room
published to the directory violates room list publication rules, the
room is still created but the room is not published to the directory.