rename the *.json.rz to *.ruby

rename the *.json.rz to *ruby - they have no json content and are not deflated ruby objects but just ruby objects.

people already tried to runzip those json.rz files which did not succeed.

these files are used as local cache of for the bundler API: /api/v1/dependencies?gems=name1,name2,... where the /api/v1/dependencies/name1.ruby is exactly the same content as /api/v1/dependencies?gems=name1