Update patch for s390x

[imsudiproy]

./build-selfhosted.sh [-b ] [distro ...] failed with patch not apply.

[Dead2]

Version is now 6.0.421, so another update needed.

I think a better solution would be to leave that change out of the patch, and use another tool to change the version number while ignoring what the build and possibly minor version number is before the change.
For example sed could be used to in-place replace the version number.

Edit: Or just replace the file with one provided by gaplib.

[v1gnesh]

@Dead2, I can help with automating ever-greening.
I've done this for another org recently, an org that has 200+ ports to keep up-to-date.
Would you consider sponsoring for this work?
I don't expect a lot; would be nice to see at least some sponsored open source work in the IBM Z ecosystem.