tailscale: add philiptaron as maintainer

I'm part of the [Tailscale Insiders](https://tailscale.com/blog/tailscale-insiders-update-seattle-meetup-news) team and am passionate about making Tailscale on Nix and NixOS the best it can be.

Author: philiptaron

pkgs/by-name/ta/tailscale/package.nix

@@ -227,6 +227,7 @@ buildGoModule (finalAttrs: {
       mbaillie
       jk
       mfrw
+      philiptaron
       pyrox0
       ryan4yin
     ];