Do not sign not deployed artifacts

Author: ppkarwasz

log4j-core-its/pom.xml

@@ -31,6 +31,7 @@
     <bnd.baseline.skip>true</bnd.baseline.skip>
     <maven.deploy.skip>true</maven.deploy.skip>
     <maven.install.skip>true</maven.install.skip>
+    <sign.skip>true</sign.skip>
     <spotbugs.skip>true</spotbugs.skip>
   </properties>
   <dependencies>

log4j-layout-template-json-test/pom.xml

@@ -32,6 +32,7 @@
   <properties>
 
     <maven.deploy.skip>true</maven.deploy.skip>
+    <sign.skip>true</sign.skip>
 
     <!--
       ~ OSGi and JPMS options

log4j-osgi-test/pom.xml

@@ -32,6 +32,8 @@
     <bnd.baseline.skip>true</bnd.baseline.skip>
     <maven.deploy.skip>true</maven.deploy.skip>
     <maven.install.skip>true</maven.install.skip>
+    <sign.skip>true</sign.skip>
+
     <spotbugs.skip>true</spotbugs.skip>
     <spifly.version>1.3.7</spifly.version>
   </properties>

log4j-perf-test/pom.xml

@@ -35,6 +35,8 @@
     <maven.test.skip>true</maven.test.skip>
     <maven.deploy.skip>true</maven.deploy.skip>
     <maven.install.skip>true</maven.install.skip>
+    <sign.skip>true</sign.skip>
+
     <module.name>org.apache.logging.log4j.perf</module.name>
     <maven.compiler.release>9</maven.compiler.release>
     <surefire.jdkToolchain>[9, )</surefire.jdkToolchain>