ci: bump Python to v3.12

Bump the version of Python used in CI to v3.12.

Signed-off-by: Henrik Brix Andersen <[email protected]>

Author: henrikbrixandersen

.github/workflows/build.yml

@@ -22,7 +22,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: 3.11
+          python-version: 3.12
 
       - name: Setup Zephyr project
         uses: zephyrproject-rtos/action-zephyr-setup@v1