py-numpy: updated to 1.20.3

1.20.3:
BUG: Correct ``datetime64`` missing type overload for ``datetime.date``
MAINT: Remove ``__all__`` in favor of explicit re-exports
BLD: Strip extra newline when dumping gfortran version on MacOS
BUG: fix segfault in object/longdouble operations
MAINT: Use towncrier build explicitly
MAINT: Relax certain integer-type constraints
MAINT: Remove unsafe unions and ABCs from return-annotations
MAINT: Allow more recursion depth for scalar tests.
BUG: Initialize the full nditer buffer in case of error
BLD: remove unnecessary flag ``-faltivec`` on macOS
MAINT, CI: treats _SIMD module build warnings as errors through...
BUG: for MINGW, threads.h existence test requires GLIBC > 2.12
BUG: Make changelog recognize gh- as a PR number prefix.
REL, DOC: Prepare for the NumPy 1.20.3 release.
BUG: Fix failing mypy test in 1.20.x.

(adam)