pivy - new upstream 0.6.6

[Ileana Dumitrescu]

Hello,

I noticed pivy as another debian-science package that failed to build with riscv. I updated the upstream version to 0.6.6 and the package built successfully with riscv without any more changes needed. I submitted merge requests on the pivy salsa page for the master, upstream, and pristine-tar branches.

Please let me know if there are any issues.

Ileana Dumitrescu