remove upper bound from numpy version (#347)

* remove upper bound from numpy version

* require older numpy on 3.9

crick version 0.6.0 is the last version to support 3.9. It is compiled against numpy <2.0.0

setup.py

@@ -18,9 +18,6 @@
 numpy_constraints = (
     ">=1.15",
     "!=1.17.0",
-    # TODO: drop this once all deps support numpy 2.0
-    # see https://github.com/dask/crick/issues/53
-    "<2",
 )
 numpy_version = ",".join(numpy_constraints)
 
@@ -82,6 +79,7 @@
         "tqdm",
     ],
     extras_require={
+        ':python_version == "3.9"': ["numpy<2.0.0"],
         "test": [
             "pytest",
             "pytest-cov",