fix: Mark internal config repo as reproducible for Bzlmod (bazel-contrib#3544)

When I updated past 1.6.3, I noticed that my MODULE.bazel.lock was being
updated with locking details of the internal dependencies of
rules_python. My understanding is that `http_archive` and non-watched
repository files tend to be easy to mark reproducible, which avoids
unnecessary updates to the lockfile. I have verified this on an internal
project that this does what I expect it to.

Author: aaronsky

python/extensions/BUILD.bazel

@@ -47,5 +47,6 @@ bzl_library(
     deps = [
         "//python/private:internal_config_repo_bzl",
         "//python/private/pypi:deps_bzl",
+        "@bazel_features//:features",
     ],
 )

python/extensions/config.bzl

@@ -1,5 +1,6 @@
 """Extension for configuring global settings of rules_python."""
 
+load("@bazel_features//:features.bzl", "bazel_features")
 load("//python/private:internal_config_repo.bzl", "internal_config_repo")
 load("//python/private/pypi:deps.bzl", "pypi_deps")
 
@@ -21,10 +22,10 @@ to repositories that are expensive to create or invalidate frequently.
     },
 )
 
-def _config_impl(mctx):
+def _config_impl(module_ctx):
     transition_setting_generators = {}
     transition_settings = []
-    for mod in mctx.modules:
+    for mod in module_ctx.modules:
         for tag in mod.tags.add_transition_setting:
             setting = str(tag.setting)
             if setting not in transition_setting_generators:
@@ -40,6 +41,11 @@ def _config_impl(mctx):
 
     pypi_deps()
 
+    if bazel_features.external_deps.extension_metadata_has_reproducible:
+        return module_ctx.extension_metadata(reproducible = True)
+    else:
+        return None
+
 config = module_extension(
     doc = """Global settings for rules_python.