Add new rvm control files to ignores

[#49402505]

rvm stable (1.19.6) has deprecated .rvmrc in favor of the .ruby-version
file used by other ruby version switchers and .ruby-gemset.  These files
only contain strings to be looked up instead of bash or sh code, so it's
also a safer format than the old script in the .rvmrc.
Merge pull request #1802 from limhoff-r7/feature/new-rvm-ignores

[Delivers #49402505]