[maven-release-plugin] prepare for next development iteration

pom.xml

@@ -4,7 +4,7 @@
 
   <groupId>de.muehlencord.mapstruct</groupId>
   <artifactId>mapstruct-support</artifactId>
-  <version>1.6.3</version>
+  <version>1.6.4-SNAPSHOT</version>
 
   <properties>
     <java.version>21</java.version>
@@ -40,7 +40,7 @@
   <scm>
     <connection>scm:git:https://jomu.timelord.de/git/jomu/mapstruct-support</connection>
     <developerConnection>scm:git:git@jomu.timelord.de:jomu/mapstruct-support.git</developerConnection>
-    <tag>mapstruct-support-1.6.3</tag>
+    <tag>HEAD</tag>
   </scm>
 
   <developers>