MODULE.bazel: Revert removal of python toolchain

Add definition and config for python toolchain since it is needed for
docs-as-code.

Author: umaucher

MODULE.bazel

@@ -17,6 +17,18 @@ module(
 )
 
 ## Toolchains (dependencies and config)
+# python
+bazel_dep(name = "rules_python", version = "1.6.3")
+
+PYTHON_VERSION = "3.12"
+
+python = use_extension("@rules_python//python/extensions:python.bzl", "python")
+python.toolchain(
+    is_default = True,
+    python_version = PYTHON_VERSION,
+)
+use_repo(python)
+
 # rust
 bazel_dep(name = "rules_rust", version = "0.65.0")