.github/workflows/release.yml: Fix release

When #294, I didn't notice that the python version was not inside
quotes, leading to python version being parsed as 3.1 and not 3.10.
Breaking the release workflow.
Add missing quotes.

Signed-off-by: Arnaud Patard <arnaud.patard@collabora.com>

Author: apatard

.github/workflows/release.yml

@@ -22,7 +22,7 @@ jobs:
       - name: Switch to using Python 3.10 by default
         uses: actions/setup-python@v5
         with:
-          python-version: 3.10
+          python-version: "3.10"
 
       - name: Install tox
         run: >-