Update ph_authors.yml

[anisa-hawes]

I am updating ph_authors.yml to reflect changes on the French editorial team.

• Add new entry for Vy Cao (see Orientation tasks for Vy Cao #3850)
• Change Daphné's email contact to francais@programminghistorian.org (Managing Editor's email)

Checklist

• Assign yourself in the "Assignees" menu
• Add the appropriate "Label"
• If this PR closes an Issue, add the phrase Closes #ISSUENUMBER to your summary above
• Ensure the status checks pass: if you have difficulty fixing build errors, please contact our Publishing Manager @anisa-hawes
• Check the Netlify Preview: navigate to netlify/ph-preview/deploy-preview and click 'details' (at right)
• Assign at least one individual or team to "Reviewers"
  • if the text needs to be translated, please follow the translation request guidelines, then assign the relevant language team(s) as "Reviewers" and tag both the team as well as the managing editor in your PR.

[anisa-hawes]

Bonjour @DMathelier,

This PR is ready for your review. It adds Vy's profile to our Project Team pages.

At the same time, I've updated your email as I noticed I hadn't added the francais@programminghistorian.org as the key contact.

(I'll prepare a separate PR to add Ilyes's profile, as I have not yet received their profile portrait).

Merci,
Anisa