chore: extra code removals before 1.0 (#2421)

Alternatives have existed for a long time and we just ensure that
we remove before the 1.0 release.

Summary:
- remove pip_install_dependencies
- remove DEFAULT_PYTHON_VERSION from interpreters.bzl

Work towards #1361

Author: aignas

CHANGELOG.md

@@ -97,7 +97,10 @@ Other changes:
 
 {#v0-0-0-removed}
 ### Removed
-* Nothing removed.
+* (pypi): Remove `pypi_install_dependencies` macro that has been included in
+  {bzl:obj}`py_repositories` for a long time.
+* (bzlmod): Remove `DEFAULT_PYTHON_VERSION` from `interpreters.bzl` file. If
+  you need the version, please use it from the `versions.bzl` file instead.
 
 {#v0-40-0}
 ## [0.40.0] - 2024-11-17

examples/bzlmod/MODULE.bazel.lock

@@ -35,14 +35,6 @@ bzl_library(
     deps = ["//python/private/pypi:pip_compile_bzl"],
 )
 
-bzl_library(
-    name = "repositories_bzl",
-    srcs = ["repositories.bzl"],
-    deps = [
-        "//python/private/pypi:deps_bzl",
-    ],
-)
-
 filegroup(
     name = "distribution",
     srcs = glob(["**"]),

python/pip_install/BUILD.bazel

@@ -86,7 +86,6 @@ _interpreters_bzl_template = """
 INTERPRETER_LABELS = {{
 {interpreter_labels}
 }}
-DEFAULT_PYTHON_VERSION = "{default_python_version}"
 """
 
 _line_for_hub_template = """\
@@ -125,8 +124,6 @@ def _hub_repo_impl(rctx):
     rctx.file(
         "interpreters.bzl",
         _interpreters_bzl_template.format(
-            # TODO @aignas 2024-09-28: before 1.0 remove the value from here
-            default_python_version = rctx.attr.default_python_version,
             interpreter_labels = interpreter_labels,
         ),
         executable = False,

python/pip_install/repositories.bzl

@@ -7,15 +7,6 @@ load("@rules_python//python:repositories.bzl", "py_repositories", "python_regist
 
 py_repositories()
 
-# This call is included in `py_repositories` and we are calling
-# `pip_install_dependencies` only to ensure that we are not breaking really old
-# code.
-#
-# TODO @aignas 2024-06-23: remove this before 1.0.0
-load("@rules_python//python/pip_install:repositories.bzl", "pip_install_dependencies")
-
-pip_install_dependencies()
-
 python_register_toolchains(
     name = "python39",
     python_version = "3.9",