Using Fedora 31, this has been happening for quite a while. After reboot /var/run/clamav is removed, which is expected. However, wehn ClamAV was installed the user created in /etc/passwd looks like this:
clamav:x:985:981::/var/run/clamav:/sbin/nologin

So Pulseaudio tries to create the following directories/files:

Aug  5 10:14:02 myuser pulseaudio[1392074]: E: [pulseaudio] core-util.c: Failed to create secure directory (/var/run/clamav/.config/pulse): No such file or directory
Aug  5 10:14:02 myuser systemd[1392030]: pulseaudio.service: Main process exited, code=exited, status=1/FAILURE
Aug  5 10:14:02 myuser systemd[1392030]: pulseaudio.service: Failed with result 'exit-code'.
Aug  5 10:14:02 myuser systemd[1392030]: Failed to start Sound Service.
Aug  5 10:14:02 myuser systemd[1392030]: pulseaudio.service: Scheduled restart job, restart counter is at 2.
Aug  5 10:14:02 myuser systemd[1392030]: Stopped Sound Service.
Aug  5 10:14:02 myuser systemd[1392030]: Starting Sound Service...

So a work-around I've found is to update /lib/systemd/system/clamd.service with:

ExecStartPre = /usr/bin/mkdir -p /var/run/clamav
ExecStartPre = /usr/bin/chown -R clamav.clamav /var/run/clamav

Is this a known issue?