Downgrade numpy build requirement from 1.21.4 to 1.21.1

In principle, it is possible to use NumPy up to version 1.21.4
when building for Python >= 3.7, but the problem is that NumPy
versions from 1.21.2 to 1.21.6 add an explicit upper pin '<3.11'
which prevents `basemap` from being built successfully with the
recently released Python 3.11.

Since the goal here is to build the wheels with an old-enough
NumPy, we try here by downgrading NumPy at the build stage from
1.21.4 to 1.21.1, since NumPy 1.21.1 did not have this '<3.11'.

Note that we cannot go below NumPy 1.21.0 because then the MacOS
builds will fail due to a NumPy build bug.

Author: molinav

.github/workflows/basemap-for-manylinux.yml

@@ -158,7 +158,7 @@ jobs:
           case "${{ matrix.python-version }}" in
               2.6|3.[23])      pkgvers=1.11.3;;
               2.7|3.[456789])  pkgvers=1.16.6;;
-              *)               pkgvers=1.21.4;;
+              *)               pkgvers=1.21.1;;
           esac
           pip install "numpy == ${pkgvers}"
       -

.github/workflows/basemap-for-windows.yml

@@ -179,7 +179,7 @@ jobs:
           Switch -regex ("${{ matrix.python-version }}") {
               "^2\.6|3\.[123]$"     { Set-Variable -Name "pkgvers" -Value "1.11.3" }
               "^2\.7|3\.[456789]$"  { Set-Variable -Name "pkgvers" -Value "1.16.6" }
-              default               { Set-Variable -Name "pkgvers" -Value "1.21.4" }
+              default               { Set-Variable -Name "pkgvers" -Value "1.21.1" }
           }
           $env:SETUPTOOLS_USE_DISTUTILS = "stdlib"
           python -m pip install "numpy == ${pkgvers}"

packages/basemap/pyproject.toml

@@ -2,8 +2,8 @@
 requires = [
     'setuptools',
     'wheel',
-    'numpy == 1.21.4; python_version >= "3.10"',
-    'numpy == 1.21.4; sys_platform == "darwin" and (python_version >= "3.7" and python_version <= "3.9")',
+    'numpy == 1.21.1; python_version >= "3.10"',
+    'numpy == 1.21.1; sys_platform == "darwin" and (python_version >= "3.7" and python_version <= "3.9")',
     'numpy == 1.16.6; sys_platform != "darwin" and (python_version >= "3.7" and python_version <= "3.9")',
     'numpy == 1.16.6; python_version == "2.7" or (python_version >= "3.4" and python_version <= "3.6")',
     'numpy == 1.11.3; python_version == "2.6" or (python_version >= "3.2" and python_version <= "3.3")',