Switch Quilt and Purpur to image helper (#2229)

tests/setuponlytests/auto_curseforge/docker-compose.yml

@@ -6,7 +6,7 @@ services:
     environment:
       EULA: "true"
       SETUP_ONLY: "TRUE"
-      TYPE: AUTO_CURSEFORGE
+      MOD_PLATFORM: AUTO_CURSEFORGE
       CF_API_KEY: ${CF_API_KEY}
       CF_SLUG: the-pixelmon-modpack
       CF_FILENAME_MATCHER: "9.1.2"

tests/setuponlytests/modrinth/docker-compose.yml

@@ -7,10 +7,7 @@ services:
       EULA: "true"
       SETUP_ONLY: "true"
       TYPE: FABRIC
-      FABRIC_LAUNCHER: /servers/fake.jar
-      CUSTOM_SERVER: /servers/fake.jar
       VERSION: 1.19.1
       MODRINTH_PROJECTS: fabric-api,cloth-config
     volumes:
       - ./data:/data
-      - ./fake.jar:/servers/fake.jar