fix version tag

Author: amoffat

.github/workflows/main.yml

@@ -148,7 +148,9 @@ jobs:
 
       - name: Get current version
         id: get_version
-        run: echo "version=$(sed -n 's/^version = "\(.*\)"/\1/p' pyproject.toml)" >> $GITHUB_ENV
+        run: |
+          version=$(sed -n 's/^version = "\(.*\)"/\1/p' pyproject.toml)
+          echo "version=$version" >> "$GITHUB_OUTPUT"
 
       - name: Set up Python
         uses: actions/setup-python@v5