Bump nutanix-cloud-native/cloud-provider-nutanix to latest release

Author: eks-distro-pr-bot

UPSTREAM_PROJECTS.yaml

@@ -251,8 +251,8 @@ projects:
     repos:
       - name: cloud-provider-nutanix
         versions:
-          - tag: v0.6.1
-            go_version: "1.24"
+          - tag: v0.6.3
+            go_version: "1.25"
       - name: cluster-api-provider-nutanix
         versions:
           - tag: v1.6.1