openblas only for mypy

Author: Alexboiboi

.github/workflows/ci.yml

@@ -58,7 +58,7 @@ jobs:
           allow-prereleases: true
 
       - name: Install OpenBLAS
-        if: runner.os == 'Linux'
+        if: runner.os == 'Linux' && startsWith(matrix.python-version, 'pypy')
         run: sudo apt-get update && sudo apt-get install -y libopenblas-dev
 
       - name: Install package