Update default Bazel versions to include 9.x

tools/registry.py

diff --git a/tools/registry.py b/tools/registry.py
index 152bae2..2939fd6 100644
--- a/tools/registry.py
+++ b/tools/registry.py
@@ -434,7 +434,7 @@
             shutil.copy(module.presubmit_yml, presubmit_yml)
         else:
             DEFAULT_PLATFORMS = ["debian11", "ubuntu2204", "macos", "macos_arm64", "windows"]
-            DEFAULT_BAZEL_VERSIONS = ["8.x", "7.x", "6.x"]
+            DEFAULT_BAZEL_VERSIONS = ["9.x", "8.x", "7.x"]
             platforms = module.matrix_platforms or DEFAULT_PLATFORMS
             bazel_versions = module.matrix_bazel_versions or DEFAULT_BAZEL_VERSIONS
             presubmit = {