BLD: update build requirement for py39 #37135 (#37144)

Author: fangchenli

pyproject.toml

@@ -6,9 +6,10 @@ requires = [
     "wheel",
     "Cython>=0.29.21,<3",  # Note: sync with setup.py
     "numpy==1.16.5; python_version=='3.7' and platform_system!='AIX'",
-    "numpy==1.17.3; python_version>='3.8' and platform_system!='AIX'",
+    "numpy==1.17.3; python_version=='3.8' and platform_system!='AIX'",
     "numpy==1.16.5; python_version=='3.7' and platform_system=='AIX'",
-    "numpy==1.17.3; python_version>='3.8' and platform_system=='AIX'",
+    "numpy==1.17.3; python_version=='3.8' and platform_system=='AIX'",
+    "numpy; python_version>='3.9'",
 ]
 
 [tool.black]