ProtobufExtract filteredProtos and normalization

In our project we have metadata in `META-INF/MANIFEST.MF` which we're currently ignoring [ignoring](https://docs.gradle.org/current/javadoc/org/gradle/normalization/MetaInfNormalization.html#ignoreCompletely--)

But when comparing builds we see `extractIncludeProtos` keep appearing on account of `filteredProtos` having jar-files with different content.

And this makes me wonder, shouldn't `extractIncludeProtos` be annotated with [@Classpath](https://docs.gradle.org/current/javadoc/org/gradle/api/tasks/Classpath.html) rather than `@InputFiles`?

Going by `The content of the jar file is normalized so that time stamps and order of the zip entries in the jar file do not matter.` this sounds like it'd be a perfect fit