release: prepare for further development on 1.9.1

Author: zml2008

build.gradle

@@ -23,7 +23,7 @@ compileJava {
 group = 'org.vineflower'
 archivesBaseName = 'vineflower'
 
-version = '1.9.0'
+version = '1.9.1'
 
 def ENV = System.getenv()
 version = version + (ENV.GITHUB_ACTIONS ? "" : "+local")