Remove bzl_library from python/pip_install/BUILD so that skylib dep is not exposed to end-users (#430)

docs/BUILD

diff --git a/docs/BUILD b/docs/BUILD
index 4da9d80..69efa78 100644
--- a/docs/BUILD
+++ b/docs/BUILD
@@ -54,6 +54,14 @@
     deps = [":bazel_python_tools"],
 )
 
+bzl_library(
+    name = "pip_install_bzl",
+    srcs = [
+        "//python/pip_install:pip_repository.bzl",
+        "//python/pip_install:repositories.bzl",
+    ],
+)
+
 stardoc(
     name = "core-docs",
     out = "python.md",
@@ -71,7 +79,7 @@
     input = "//python:pip.bzl",
     deps = [
         ":bazel_repo_tools",
-        "//python/pip_install:bzl",
+        ":pip_install_bzl",
     ],
 )
 

python/pip_install/BUILD

diff --git a/python/pip_install/BUILD b/python/pip_install/BUILD
index b37170e..c24e6c7 100644
--- a/python/pip_install/BUILD
+++ b/python/pip_install/BUILD
@@ -1,5 +1,3 @@
-load("@bazel_skylib//:bzl_library.bzl", "bzl_library")
-
 filegroup(
     name = "distribution",
     srcs = glob(["*.bzl"]) + [
@@ -9,11 +7,7 @@
     visibility = ["//:__pkg__"],
 )
 
-bzl_library(
-    name = "bzl",
-    srcs = [
-        "pip_repository.bzl",
-        "repositories.bzl",
-    ],
+exports_files(
+    ["pip_repository.bzl", "repositories.bzl"],
     visibility = ["//docs:__pkg__"],
 )