[maven-release-plugin] prepare release dlcm-1.9.0

pom.xml

 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
 
     <groupId>ch.dlcm</groupId>
     <artifactId>dlcm-portal</artifactId>
     <packaging>pom</packaging>
-    <version>1.9.0-SNAPSHOT</version>
+    <version>1.9.0</version>
 
     <properties>
         <!-- Base web context used for the Angular application -->
@@ -19,7 +18,7 @@
 
     <scm>
         <connection>scm:git:git@gitlab.unige.ch:dlcm/ui/dlcm-portal.git</connection>
-        <tag>HEAD</tag>
+        <tag>dlcm-1.9.0</tag>
     </scm>
 
     <distributionManagement>