20.04 Install includes /etc/apt/sources.list.d/bionic-security.list

[Colin Law]

I did a fresh install of Ubuntu 20.04 desktop (focal) some weeks ago
and have just noticed that it is looking for updates in
bionic-security.  The reason is that /etc/apt/sources.list.d  contains
a file bionic-security.list containing
deb http://security.ubuntu.com/ubuntu bionic-security main
Should it be there and if (as I presume) not, any ideas on how it
might have got there?

Should I just remove it?

Colin