pylibraft only depends on numpy at runtime, not build time. (#2013)

pylibraft specifies its numpy pinning incorrectly in conda packages. It is only a runtime dependency, not a build dependency. Because of run-exports from numpy, the resulting pinning on pylibraft requires a very new numpy version, and is thus causing cuml to fall back to old raft builds.

Authors:
  - Bradley Dice (https://github.com/bdice)

Approvers:
  - Dante Gama Dessavre (https://github.com/dantegd)
  - Mark Harris (https://github.com/harrism)
  - Vyas Ramasubramani (https://github.com/vyasr)
  - Ray Douglass (https://github.com/raydouglass)

URL: rapidsai/raft#2013

conda/recipes/pylibraft/meta.yaml

@@ -48,7 +48,6 @@ requirements:
     - cython >=3.0.0
     - libraft {{ version }}
     - libraft-headers {{ version }}
-    - numpy >=1.21
     - python x.x
     - rmm ={{ minor_version }}
     - scikit-build >=0.13.1
@@ -60,6 +59,7 @@ requirements:
     {% endif %}
     - libraft {{ version }}
     - libraft-headers {{ version }}
+    - numpy >=1.21
     - python x.x
     - rmm ={{ minor_version }}