build: Bump version to 6.4.1-SNAPSHOT.

Change-Id: I847ffe943cf6cff82efdf0d873d3acee53f563df
diff --git a/pom.xml b/pom.xml
index 7ac14a3..0054423 100644
--- a/pom.xml
+++ b/pom.xml
@@ -12,7 +12,7 @@
   <modelVersion>4.0.0</modelVersion>
 
   <groupId>eu.mulk.quarkus-googlecloud-jsonlogging</groupId>
-  <version>6.4.0</version>
+  <version>6.4.1-SNAPSHOT</version>
 
   <artifactId>quarkus-googlecloud-jsonlogging-parent</artifactId>
   <packaging>pom</packaging>