Make build reproducible.

By removing timestamp from build info file.
This is helpful for git ops, because we using the image's repo digest, only changes to the code trigger a change in the GitOps repo.
Right now, there still is this issue: https://github.com/paketo-buildpacks/builder/issues/45

pom.xml

@@ -198,6 +198,7 @@
               <goal>build-info</goal>
             </goals>
             <configuration>
+              <time>off</time>
               <additionalProperties>
                 <encoding.source>${project.build.sourceEncoding}</encoding.source>
                 <encoding.reporting>${project.reporting.outputEncoding}</encoding.reporting>