FIX: Use quotes for Python version

YAML gotcha 3.10 -> 3.1, versions should be quoted.

Author: ghisvail

.github/workflows/testdask.yml

@@ -12,7 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.9, 3.10, 3.11]
+        python-version: ['3.9', '3.10', '3.11']
       fail-fast: false
 
     steps:
@@ -39,4 +39,4 @@ jobs:
           pytest -v --dask pydra/engine --cov pydra --cov-config .coveragerc --cov-report xml:cov.xml
 
       - name: Upload to codecov
-        run: codecov -f cov.xml -F unittests -e GITHUB_WORKFLOW
+        run: codecov -f cov.xml -F unittests -e GITHUB_WORKFLOW