Merge the determinism changes into Py3 upgrade branch

Step one in the slow process of getting the Python 3/Gstreamer 1.0 upgrade branch merged back together with spiir-O4-EW-development.

These are Gozz’s determinism-related fixes, mostly in finalsink.

Note that one of the changes was to force FFTW to deterministically select its FFT algorithm which took place in gstlal itself. Because gstlal and friends has been removed from this branch, that change is not included but will need to be merged separately into Gstlal.

Note also that there is an extra change to the Makefile, removing all the old -gencode sm_XX, where XX listed all the really ancient computer modes that we were compiling for. If I don’t do this, when building on OzStar, I get the complaint __shfl_down is not defined. I am open to other approaches to this problem, particularly if it turns out those older versions are necessary for some/all of the CIT nodes.