Vulnerability reports not triggering cache purge

[di]

On vulnerability report updates like #12767, this is not triggering cache purging for the JSON API, which leads to these responses being out of date after an update.

[nnja]

@di Do you have further information on how to reproduce the issue?

@ewdurbin and I tried to repro over the weekend, unsuccessfully.

[di]

After chatting with @ewdurbin it seems likely that this was due to #12214.

[di]

Closing as this was due to #12214.