chore: update version to 15.4.0 (#5)

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Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: marevol

pom.xml

@@ -6,7 +6,7 @@
 	<artifactId>fess-webapp-example</artifactId>
 	<packaging>jar</packaging>
 	<name>Example Webapp Plugin</name>
-	<version>15.3.0-SNAPSHOT</version>
+	<version>15.4.0-SNAPSHOT</version>
 	<scm>
 		<connection>scm:git:git@github.com:codelibs/fess-webapp-example.git</connection>
 		<developerConnection>scm:git:git@github.com:codelibs/fess-webapp-example.git</developerConnection>
@@ -15,7 +15,7 @@
 	<parent>
 		<groupId>org.codelibs.fess</groupId>
 		<artifactId>fess-parent</artifactId>
-		<version>15.3.0</version>
+		<version>15.4.0</version>
 		<relativePath />
 	</parent>
 	<build>