Fix func worker segfault on Python 3.13 by redirecting worker to Python 3.12

The Azure Functions Python worker crashes with SIGSEGV (exit code 139)
on Python 3.13 due to protobuf C extension (google._upb) compatibility
issues.  When the test runner uses Python >=3.13, the conftest now
automatically finds a compatible Python 3.10-3.12 and sets
languageWorkers__python__defaultExecutablePath so the func host uses
it for the worker process.

The CI setup action also ensures Python 3.12 is available on the
runner, falling back to uv python install if the system doesn't have
it.

Co-authored-by: larohra <41490930+larohra@users.noreply.github.com>

.github/actions/azure-functions-integration-setup/action.yml

@@ -46,3 +46,18 @@ runs:
           echo "Installing Azure Functions Core Tools"
           npm install -g azure-functions-core-tools@4 --unsafe-perm true
           func --version
+      - name: Ensure Python 3.12 is available for Azure Functions worker
+        shell: bash
+        run: |
+          # The Azure Functions Python worker may segfault on Python >=3.13
+          # (protobuf C extension crash).  Ensure a compatible Python is
+          # available so the conftest can redirect the worker to it.
+          if ! python3.12 --version 2>/dev/null; then
+            echo "Python 3.12 not found on system, installing via uv..."
+            uv python install 3.12
+            FUNC_WORKER_PYTHON="$(uv python find 3.12)"
+            echo "FUNC_WORKER_PYTHON=${FUNC_WORKER_PYTHON}" >> "$GITHUB_ENV"
+            echo "Installed Python 3.12 at ${FUNC_WORKER_PYTHON}"
+          else
+            echo "System Python 3.12 found: $(which python3.12)"
+          fi