Update Ubuntu version for GitHub runner

Author: mstimberg

.github/workflows/publish_to_pypi.yml

@@ -4,7 +4,7 @@ on: [push, pull_request]
 jobs:
   build-n-publish:
     name: Build package and publish to (Test)PyPI
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-24.04
     steps:
       - uses: actions/checkout@v2
         with: