BUG: Relax homogeneous signature fallback in type resolution

Relaxing the fallback means that reductions, which pass
`(dtype, None, dtype)` as signature (`type_tup` in the old resolver)
can resolve to the homogeneous loop if `dtype=dtype` is passed.

This change is important, because the resolution changed from using
`(None, None, dtype)` to `(dtype, None, dtype)` since reductions
normally are expected to have the first input match the output.

Specifying the signature more precisly without also relaxing the
"homogeneous" fallback, however, lead to a regression noticed
by Pandas.

Closes gh-20151

0 files changed, 0 insertions, 0 deletions