[pydrake] Remove workaround for bazel#4594 (#21748)

bindings/BUILD.bazel

@@ -1,27 +1,3 @@
 load("//tools/lint:lint.bzl", "add_lint_tests")
-load(
-    "//tools/skylark:pybind.bzl",
-    "drake_pybind_library",
-)
-load(
-    ":bazel_workaround_4594_libdrake.bzl",
-    "get_bazel_workaround_4594_libdrake_package_info",
-)
-
-package(default_visibility = [
-    "//bindings/pydrake:__subpackages__",
-])
-
-# This is placed outside of `pydrake` so that we can import this without
-# pulling in an extra copy of `pydrake`. For more information, see
-# `pydrake/__init__.py`.
-drake_pybind_library(
-    name = "bazel_workaround_4594_libdrake_py",
-    add_install = False,
-    cc_srcs = ["bazel_workaround_4594_libdrake_py.cc"],
-    # Since `package_info` must be a `struct`, we must define this in a `*.bzl`
-    # file.
-    package_info = get_bazel_workaround_4594_libdrake_package_info(),
-)
 
 add_lint_tests(cpplint_data = ["//bindings/pydrake:.clang-format"])

bindings/pydrake/BUILD.bazel

@@ -47,7 +47,6 @@ drake_py_library(
         "__init__.py",
     ],
     deps = [
-        "//bindings:bazel_workaround_4594_libdrake_py",
         "//bindings/pydrake/common:_init_py",
     ],
 )

bindings/pydrake/__init__.py

@@ -18,23 +18,6 @@
 import sys
 import warnings
 
-# When importing `pydrake` as an external under Bazel, Bazel will use a shared
-# library whose relative RPATHs are incorrect for `libdrake.so`, and thus will
-# fail to load; this issue is captured in bazelbuild/bazel#4594. As a
-# workaround, we can use a library that properly links to `libdrake.so`, but in
-# `{runfiles}/{workspace}/external/drake` rather than `{runfiles}/drake`.
-# Once this is loaded, all of the Python C-extension libraries
-# that depend on it (and its dependencies) will load properly.
-# Please note that this workaround is only important when running under the
-# Bazel runfiles tree. Installed `pydrake` should not have this issue.
-# N.B. We do not import `external.drake.bindings.pydrake` as this may cause
-# duplicate classes to be loaded (#8810). This will not be a problem once #7912
-# is resolved.
-try:
-    import external.drake.bindings.bazel_workaround_4594_libdrake
-except ImportError:
-    pass
-
 
 def getDrakePath():
     # Compatibility alias.