add 1.13.1 to old versions on develop (#5759)

diff --git a/settings.gradle b/settings.gradle
index 5295172..3026fca 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -87,7 +87,8 @@
  '1.10.0',
  '1.11.0',
  '1.12.0',
- '1.13.0'].each {
+ '1.13.0',
+ '1.13.1'].each {
   include 'geode-old-versions:'.concat(it)
 }