science/py-h5py: unbreak packaging with python!= 3.9

pkg-static: Unable to access file /wrkdirs/usr/ports/science/py-h5py/work-py310/stage/usr/local/share/doc/py310-h5py/whatsnew/3.10.rst:No such file or directory

Versioned release notes files shouldn't be covered with %%PYTHON_VER%% macro.

No PORTREVISION bump, python 3.9 is a default version and package content isn't changed.

Reported by: poudriere failure
Approved by: portmgr blanket (trivial fix)