Revert "Disable "cancel-in-progress" temporarily so we can see the full matrix of CI results"

This reverts commit 8a945f7.
Signed-off-by: Joshua Minor <joshm@pixar.com>

Author: jminor

.github/workflows/python-package.yml

@@ -17,7 +17,7 @@ on:
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
-  # cancel-in-progress: true
+  cancel-in-progress: true
 
 jobs:
   cpp_build: