Note optional Element Commecial License in SPDX specifiers

As it's possible to get an Element Commercial License exception for
Synapse, we should note this in our various license specifiers.

Author: anoadragon453

debian/copyright

@@ -8,7 +8,7 @@ License: Apache-2.0
 
 Files: *
 Copyright: 2023 New Vector Ltd
-License: AGPL-3.0-or-later
+License: AGPL-3.0-or-later or LicenseRef-Element-Commercial
 
 Files: synapse/config/saml2.py
 Copyright: 2015, Ericsson

docker/Dockerfile

@@ -174,7 +174,7 @@ ARG TARGETARCH
 LABEL org.opencontainers.image.url='https://matrix.org/docs/projects/server/synapse'
 LABEL org.opencontainers.image.documentation='https://github.com/element-hq/synapse/blob/master/docker/README.md'
 LABEL org.opencontainers.image.source='https://github.com/element-hq/synapse.git'
-LABEL org.opencontainers.image.licenses='AGPL-3.0-or-later'
+LABEL org.opencontainers.image.licenses='AGPL-3.0-or-later OR LicenseRef-Element-Commercial'
 
 # On the runtime image, /lib is a symlink to /usr/lib, so we need to copy the
 # libraries to the right place, else the `COPY` won't work.

pyproject.toml

@@ -104,7 +104,7 @@ name = "matrix-synapse"
 version = "1.138.2"
 description = "Homeserver for the Matrix decentralised comms protocol"
 authors = ["Matrix.org Team and Contributors <packages@matrix.org>"]
-license = "AGPL-3.0-or-later"
+license = "AGPL-3.0-or-later OR LicenseRef-Element-Commercial"
 readme = "README.rst"
 repository = "https://github.com/element-hq/synapse"
 packages = [