Adds configuration to ignore revs in blame (#8933)
Adds configuration to ignore revs in blame (#8933)

There have been a couple commits that touched most of the files in the
repository, especially when applying the Black formatter. The
.git-blame-rev-ignore file tells git blame to ignore those commits when
computing the blame for a file.
jakirkham/dask,dask/dask,jakirkham/dask,dask/dask