How to make viewforum.php?foo=bar request serve a file instead of a PHP code?

I’m archiving a phpBB forum into flat HTML files, without any PHP code anymore.
I used wget (see How to: Archive a phpBB forum using Wget and preserve styling), and I now have these files:

enter image description here

How to make that Apache will serve example.com/forum/viewforum.php?f=2&start=25 as a file, and not as a request to viewforum.php with a query string? The latter does not work obviously and gives a 404.

I already tried this htaccess with no success:

RemoveHandler .php .phtml .php3
RemoveType .php .phtml .php3
php_flag engine off

Note: this is how I archived the forum:

wget -m -p -np -R "*sid=*,ucp.php*,memberlist.php*,*mode=viewprofile*,*view=print*,viewonline.php*,search.php*,posting.php*" https://forums.example.com