Add runs-on

Author: awalker4

.github/workflows/speakeasy_sdk_generation.yml

@@ -15,6 +15,7 @@ permissions:
         - cron: 0 0 * * *
 jobs:
     setup-python:
+        runs-on: ubuntu-latest
         steps:
           - name: Set up Python 3.11
             uses: actions/setup-python@v2