pythonGH-127432: add cross-build-linux as a required CI job (python#129459)

Author: FFY00

.github/workflows/build.yml

@@ -621,6 +621,7 @@ jobs:
     - build_wasi
     - build_windows
     - build_windows_msi
+    - cross-build-linux
     - test_hypothesis
     - build_asan
     - build_tsan