MDL-83268 core_h5p: Remove unused font files

In https://h5ptechnology.atlassian.net/browse/HFP-4105, the
fonts/h5p-core-29.svg was merged with some conflicts.
Looking at the patch there, it seems all the h5p-core-29* fonts
can be removed because the ones used by the library are the
h5p-core-30-*.

I haven't added a note in the upgrade because it seems an error
on their release process (so I don't think it's worth adding
a note because it should be fixed in future releases).