Remove PROJECT_FLASH from libcuml conda build environment. (rapidsai#…

…5108)

This is a small cleanup to remove the outdated `PROJECT_FLASH` environment variable from the libcuml recipe.

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

Approvers:
  - AJ Schmidt (https://github.com/ajschmidt8)
  - Dante Gama Dessavre (https://github.com/dantegd)

URL: rapidsai#5108

conda/recipes/libcuml/meta.yaml

@@ -19,7 +19,6 @@ build:
     - AWS_ACCESS_KEY_ID
     - AWS_SECRET_ACCESS_KEY
     - PARALLEL_LEVEL
-    - PROJECT_FLASH
     - CMAKE_GENERATOR
     - CMAKE_C_COMPILER_LAUNCHER
     - CMAKE_CXX_COMPILER_LAUNCHER