adjust vars.cmd so it is also updated by renovate (#2169)

Author: jtnord

.github/renovate.json

@@ -51,6 +51,7 @@
       "customType": "regex",
       "managerFilePatterns": [
         "/src/main/java/org/jenkinsci/test/acceptance/FallbackConfig\\.java/",
+        "/vars.cmd/",
         "/vars.sh/"
       ],
       "matchStrings": [

vars.cmd

@@ -25,5 +25,5 @@ set TESTCONTAINERS_HOST_OVERRIDE=%IP%
 set JENKINS_LOCAL_HOSTNAME=%IP%
 @echo.
 @echo To start the remote firefox container run the following command:
-@echo docker run --shm-size=2g -d -p 127.0.0.1:4444:4444 -p 127.0.0.1:5900:5900 -e SE_NODE_GRID_URL=http://127.0.0.1:4444 -e no_proxy=localhost -e SE_SCREEN_WIDTH=1680 -e SE_SCREEN_HEIGHT=1090 selenium/standalone-firefox:4.32.0
+@echo docker run --shm-size=2g -d -p 127.0.0.1:4444:4444 -p 127.0.0.1:5900:5900 -e SE_NODE_GRID_URL=http://127.0.0.1:4444 -e no_proxy=localhost -e SE_SCREEN_WIDTH=1680 -e SE_SCREEN_HEIGHT=1090 "selenium/standalone-firefox:4.35.0"