NumPy 1.20.3 release

1. afc158d CI: Use `towncrier build` explicitly by Sebastian Berg · 4 years, 5 months ago
2. 583901a convert shebang from python to python3 (#15687) by Changqing Li · 5 years ago
3. 958a6b5 DOC,MAINT: Build release notes during CircleCI step by Sebastian Berg · 6 years ago
4. bfe255f BUILD: move all test dependencies to ./test_requirements.txt by mattip · 6 years ago
5. 01cd5c9 TST, DOC: Upload devdocs and neps after circleci build (#10702) by Stefan van der Walt · 7 years ago
6. 37878bf TST: appveyor: Enable OpenBLAS via MinGW Gfortran by xoviat · 8 years ago