Upgrade to Spring Boot 2.3.12.RELEASE.

Author: jxblum

gradle.properties

@@ -9,7 +9,7 @@ multithreadedtcVersion=1.01
 pivotalCloudCacheVersion=1.12.2
 pivotalGemFireVersion=9.10.7
 springVersion=5.2.15.RELEASE
-springBootVersion=2.3.12.BUILD-SNAPSHOT
+springBootVersion=2.3.12.RELEASE
 springDataGemFireVersion=2.3.9.RELEASE
 springDataGeodeVersion=2.3.9.RELEASE
 springDataGeodeTestVersion=0.0.20.RELEASE