make build reproducible

Signed-off-by: Lukas Jungmann <lukas.jungmann@oracle.com>
diff --git a/api/pom.xml b/api/pom.xml
index a6105e4..4f22e3b 100644
--- a/api/pom.xml
+++ b/api/pom.xml
@@ -99,6 +99,7 @@
         <implementation.vendor.id>org.glassfish</implementation.vendor.id>
 
         <maven.compiler.release>11</maven.compiler.release>
+        <project.build.outputTimestamp>2023-10-28T00:00:00Z</project.build.outputTimestamp>
     </properties>
 
     <build>
diff --git a/spec/pom.xml b/spec/pom.xml
index bb1e920..c66a34d 100644
--- a/spec/pom.xml
+++ b/spec/pom.xml
@@ -21,7 +21,7 @@
     <parent>
         <groupId>org.eclipse.ee4j</groupId>
         <artifactId>project</artifactId>
-        <version>1.0.7</version>
+        <version>1.0.9</version>
         <relativePath/>
     </parent>
 
@@ -43,6 +43,7 @@
         <!-- status: DRAFT, BETA, etc., or blank for final -->
         <status>DRAFT</status>
         <maven.build.timestamp.format>MMMM dd, yyyy</maven.build.timestamp.format>
+        <project.build.outputTimestamp>2023-10-28T00:00:00Z</project.build.outputTimestamp>
         <revisiondate>${maven.build.timestamp}</revisiondate>
     </properties>