GH-3321 Exclude package-info.class from shaded fastutil dependency

[jerolba]

Rationale for this change

I've noticed that some JARs include package-info.class files from the shaded it.unimi.dsi:fastutil dependency.

These files are located in packages that are otherwise empty and I believe these package-info.class files are unnecessary, even in artifacts that make use of other fastutil classes.

What changes are included in this PR?

Filtering these files out in the maven-shade-plugin configuration to reduce the final JAR size.

Are these changes tested?

No, apart of existing build process.

Are there any user-facing changes?

No

Closes #3321

[Fokko]

I agree that it doesn't make sense to shade package-info.class, maybe we should completely remove it:

<filters>
  <filter>
    <artifact>*:*</artifact>
    <excludes>
      <exclude>**/package-info.class</exclude>
    </excludes>
  </filter>
</filters>

[jerolba]

I have found it just from fastutil dependency.

I have no strong opinion on whether to explicitly manage this from fastutil or to generalize the rule for future changes.