feat: add fairness sponsor

Author: ginifizz

pwa/data/con/2025/partners.ts

@@ -88,6 +88,13 @@ const partners: Partner[] = [
     link: "https://yce.perfectcorp.com/fr/ai-api?utm_source=event&utm_medium=website&utm_campaign=API_Conference&utm_content=2025",
     rank: 2,
   },
+  {
+    name: "Fairness",
+    logo: "fairness",
+    link: "https://fairness.coop/",
+    rank: 2,
+    highlight: true,
+  },
   {
     name: "Darkwood",
     logo: "darkwood",