Add code owners for viral lineage assignment tools

[wm75]

FOR CONTRIBUTOR:

• [x] - I have read the CONTRIBUTING.md document and this tool is appropriate for the tools-iuc repo.
• [ ] - License permits unrestricted use (educational + commercial)
• [ ] - This PR adds a new tool or tool collection
• [ ] - This PR updates an existing tool or tool collection
• [x] - This PR does something else (explain below)

Picking up https://github.com/galaxyproject/tools-iuc/pull/4464#issuecomment-1074877902. @pvanheus if you agree of course, and putting myself there only as a backup for you.

[wm75]

Oh, can only add iuc members here it seems, hmm.

[wm75]

Now that you're a member we could finally merge this @pvanheus if you agree, of course.