attempt to fix macos-12 conda build

Signed-off-by: Nathan Goldbaum <nathan.goldbaum@gmail.com>

Author: ngoldbaum

.github/workflows/conda.yml

@@ -59,7 +59,8 @@ jobs:
           shell: micromamba-shell {0}
 
         - name: Python Build Steps
-          run: make build-conda
+          # somehow CXX is set on the macos-12 runner
+          run: CXX= make build-conda
           shell: micromamba-shell {0}
 
         - name: Python Test Steps