Use upload-artifact v4 and get latest python 3.12

.github/workflows/make_bundle.yml

@@ -44,7 +44,7 @@ jobs:
         run: |
           mkdir embedded-python
           cd embedded-python
-          curl -o python.zip https://www.python.org/ftp/python/3.12.3/python-3.12.3-embed-amd64.zip
+          curl -o python.zip https://www.python.org/ftp/python/3.12.7/python-3.12.7-embed-amd64.zip
           tar xf python.zip
           del python.zip
       - name: Edit embedded Python search paths
@@ -79,7 +79,7 @@ jobs:
         run: |
           python -c "from importlib.metadata import version; print('version=' + version('spinetoolbox'))" >> $GITHUB_OUTPUT
       - name: Upload archive
-        uses: actions/upload-artifact@v3
+        uses: actions/upload-artifact@v4
         with:
           name: Spine-Toolbox-win-${{ steps.toolbox-version.outputs.version }}
           path: "./dist/Spine Toolbox"