I’ve never seen a DELL computer that came with a LINUX OS. LINUX is free. It seems to me they wouldn’t make any money on it.
It’s not hard to change or install it yourself:
https://www.pcmag.com/how-to/how-to-make-the-switch-from-windows-to-linux
If you don’t want to bother, it probably wouldn’t cost much to pay a local geek or Computer Sci major to do it for you...
Here ya go:
Linux pre-installed on Dell desktops and laptops (www.dell.com)
You need to get out more. Dell has been selling PCs pre-installed with Linux for decades.