build: pin project.build.outputTimestamp for javadoc copyright year

The maven-javadoc-plugin derives the footer copyright year from
project.build.outputTimestamp under reproducible builds. The parent POM
pinned no timestamp, so a build run with SOURCE_DATE_EPOCH=0 floored the
year to 1980 (seen in published 2.3.0 -javadoc artifacts). Pin the
timestamp to the release date so the footer renders a real year (2026)
independent of the build environment, keeping builds reproducible.

Author: hsilan

pom.xml

@@ -54,6 +54,11 @@
         <maven.compiler.source>17</maven.compiler.source>
         <maven.compiler.target>17</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <!-- Pin the build timestamp so reproducible builds render a real
+             copyright year in generated javadoc footers. Without a pin, a
+             build run with SOURCE_DATE_EPOCH=0 floors the year to 1980.
+             Bump this on each release to the release date. -->
+        <project.build.outputTimestamp>2026-09-25T23:46:32Z</project.build.outputTimestamp>
         <aws.sdk.version>2.57.3</aws.sdk.version>
         <jackson.version>2.22.4</jackson.version>
         <junit.version>6.1.3</junit.version>