Bump the version of python used for pip. (#2130)

The default python is already 3.12 (widely available) and we should
use the same default for the pip calls too.  It's tricky to get
older python versions sometimes so this should simplify things.

MODULE.bazel

diff --git a/MODULE.bazel b/MODULE.bazel
index c162d05..ad3df4a 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -31,7 +31,7 @@
 pip = use_extension("@rules_python//python/extensions:pip.bzl", "pip", dev_dependency = True)
 pip.parse(
     hub_name = "tools_pip_deps",
-    python_version = "3.9",
+    python_version = "3.12",
     requirements_lock = "//tools:requirements.txt",
 )
 use_repo(pip, "tools_pip_deps")