feat: remove ex-staff members

data/staff.yml

@@ -189,11 +189,6 @@ staff:
     title: "Senior Research Project Manager"
     image: "./images/marco-jahn.jpg"
     username: "mjahn0qp"
-  - first_name: "John"
-    last_name: "Kellerman"
-    title: "Program Manager - Cloud Development Tools and Open VSX"
-    image: "./images/john-kellerman.jpg"
-    username: "kineticSquid"
   - first_name: "Maira"
     last_name: "Khan"
     title: "Graphic Designer"
@@ -278,11 +273,6 @@ staff:
     title: "Senior Operations Manager, Europe"
     image: "./images/silvia-miles.jpg"
     username: "smiles2ku"
-  - first_name: "Thomas"
-    last_name: "Neidhart"
-    title: "Software Engineer"
-    image: "./images/thomas-neidhart.jpg"
-    username: "netomi"
   - first_name: "Tanja"
     last_name: "Obradovic"
     title: "Senior Manager, Java Programs"