Merge pull request #196 from graphql-java-kickstart/renovate/spring-boot

chore(deps): update spring boot to v2.7.3

Author: oliemansm

gradle.properties

@@ -2,6 +2,6 @@ LIB_GRAPHQL_SERVLET_VER=13.0.1
 LIB_GRAPHQL_SPRING_BOOT_VER=12.0.0
 LIB_GRAPHQL_TOOLS_VER=13.0.0
 LIB_GRAPHQL_EXTENDED_VALIDATION_VER=18.1
-LIB_SPRING_BOOT_VER=2.7.2
+LIB_SPRING_BOOT_VER=2.7.3
 sourceCompatibility=11
 targetCompatibility=11