Merge branch 'develop' into babolivier/invite-json

.buildkite/pipeline.yml

.buildkite/synapse_sytest.sh

.github/ISSUE_TEMPLATE/SUPPORT_REQUEST.md

.github/SUPPORT.md

CHANGES.md

MANIFEST.in

UPGRADE.rst

changelog.d/4276.misc

changelog.d/5015.misc

changelog.d/5042.bugfix

changelog.d/5051.bugfix

changelog.d/5252.feature

changelog.d/5313.misc

changelog.d/5325.bugfix

changelog.d/5363.feature

changelog.d/5378.misc

changelog.d/5381.misc

changelog.d/5382.misc

changelog.d/5383.misc

changelog.d/5384.feature