[#1761] Update max java supported by Gradle to 20

For byte-code enhancements

Author: DavideD

settings.gradle

@@ -13,7 +13,7 @@ gradle.ext.baselineJavaVersion = JavaLanguageVersion.of( 11 )
 
 // Gradle does bytecode transformation on tests.
 // You can't use bytecode higher than what Gradle supports, even with toolchains.
-def GRADLE_MAX_SUPPORTED_BYTECODE_VERSION = 15
+def GRADLE_MAX_SUPPORTED_BYTECODE_VERSION = 20
 
 // If either 'main.jdk.version' or 'test.jdk.version' is set, enable the toolchain and use the selected jdk.
 // If only one property is set, the other defaults to the baseline Java version (8).