CI: disable caching of conda env so most recent versions of dependencies are used (#461)

Author: theroggy

.github/workflows/tests-conda.yml

@@ -56,7 +56,6 @@ jobs:
           create-args: >-
             python=${{ matrix.python }}
             ${{ matrix.extra }}
-          cache-environment: true
 
       - name: Set environment variables (Windows)
         if: runner.os == 'Windows'