Limit concurrent jobs [ci] (#1444)

* Limit concurrent jobs [ci]

* Run pypy together with linux

* Update timeout to 10mn instead of 5

Co-authored-by: Pierre Sassoulas <[email protected]>

Author: cdce8p

.github/workflows/ci.yaml

@@ -249,7 +249,8 @@ jobs:
   prepare-tests-windows:
     name: Prepare tests for Python ${{ matrix.python-version }} (Windows)
     runs-on: windows-latest
-    timeout-minutes: 5
+    timeout-minutes: 10
+    needs: pytest-linux
     strategy:
       matrix:
         python-version: [3.6, 3.7, 3.8, 3.9, "3.10"]