A DESCRIPTION OF THE PROBLEM :
When running javadoc for a project, it still adds a timestamp to index.html of the generated JavaDocs

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
I've created a project for reproducible build from this guide
https://maven.apache.org/guides/mini/guide-reproducible-builds.html

Plugins:

maven-jar-plugin 3.2.0
maven-javadoc-plugin 3.3.0
maven-source-plugin 3.2.1
 

This project has only one class

/**
 * Hello
 */
public class Hello {
}
 

Then I check buildinfo via

./mvnw clean verify -e -DskipTests artifact:buildinfo -Dbuildinfo.ignoreJavadoc=false


sha512 is always the same for reproducible-build-1.0-SNAPSHOT.jar and reproducible-build-1.0-SNAPSHOT-sources.jar

But for reproducible-build-1.0-SNAPSHOT-javadoc.jar it changes after each build

Cause of this behaviour is index.html file. Also can be found in target/apidocs folder after build.
It contains the line like
`<!-- Generated by javadoc (11.0.11) on Fri Jun 11 17:35:15 MSK 2021 -->`
and timestamp is different after each build



EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Timestamp should not be generated because of the setting in the maven plugin
ACTUAL -
Timestamp generated

---------- BEGIN SOURCE ----------
Here is the example

https://github.com/varpa89/reproducible-build
---------- END SOURCE ----------

FREQUENCY : always