Enable MSC3030 Complement tests in Synapse (#12144)

The Complement tests for MSC3030 are now merged, https://github.com/matrix-org/complement/pull/178

Synapse implmentation: https://github.com/matrix-org/synapse/pull/9445

.github/workflows/tests.yml

@@ -376,7 +376,7 @@ jobs:
       # Run Complement
       - run: |
           set -o pipefail
-          go test -v -json -p 1 -tags synapse_blacklist,msc2403 ./tests/... 2>&1 | gotestfmt
+          go test -v -json -p 1 -tags synapse_blacklist,msc2403,msc3030 ./tests/... 2>&1 | gotestfmt
         shell: bash
         name: Run Complement Tests
         env: