Use rpmautospec

[oturpe]

Since Rpmautospec by Default in Fedora 38, rpmautospec has been the recommended default in Fedora. Hence, I think gem2rpm should also create specfiles that use that. The change to templates is trivial, but since I know some people just do not like rpmautospec, I start with an issue to ask what would be an acceptable way to add such support. Change to the default Fedora template? Optional template with rpmautospec support? Command line parameter to enable it?