infra: replace nginx references with hanzoai/ingress

Update compose volume mounts and comments to reference hanzoai/ingress
instead of nginx for the MinIO load balancer proxy.

buildscripts/upgrade-tests/compose.yml

@@ -9,7 +9,7 @@ x-minio-common: &minio-common
     - "9001"
 
 # starts 4 docker containers running minio server instances.
-# using nginx reverse proxy, load balancing, you can access
+# using hanzoai/ingress reverse proxy, load balancing, you can access
 # it through port 9000.
 services:
   minio1:
@@ -47,7 +47,7 @@ services:
   ingress:
     image: ghcr.io/hanzoai/ingress:latest
     volumes:
-      - ./nginx.conf:/etc/nginx/nginx.conf:ro
+      - ./ingress.conf:/etc/ingress/config.yml:ro
     ports:
     - "9000:9000"
     - "9001:9001"