bindings: Remove cpp_const (RobotLocomotion#14270)

This appears to be dead code.  By dropping it, we can also drop an
awkward dependency.

bindings/pydrake/BUILD.bazel

@@ -272,7 +272,6 @@ PY_LIBRARIES_WITH_INSTALL = [
     ":polynomial_py",
     ":symbolic_py",
     ":trajectories_py",
-    "//bindings/pydrake/third_party",
     "//bindings/pydrake/visualization",
 ] + PYBIND_SUBPACKAGES_FOR_COVERAGE
 

bindings/pydrake/all.py

@@ -44,5 +44,4 @@
 from .multibody.all import *
 from .solvers.all import *
 from .systems.all import *
-# - `third_party` does not offer public Drake library symbols.
 from .visualization.all import *

bindings/pydrake/common/BUILD.bazel

@@ -265,15 +265,6 @@ drake_cc_library(
     ],
 )
 
-drake_py_library(
-    name = "cpp_const_py",
-    srcs = ["cpp_const.py"],
-    deps = [
-        ":module_py",
-        "//bindings/pydrake/third_party:wrapt_py",
-    ],
-)
-
 drake_cc_library(
     name = "sorted_pair_pybind",
     hdrs = ["sorted_pair_pybind.h"],
@@ -354,7 +345,6 @@ PY_LIBRARIES_WITH_INSTALL = [
 PY_LIBRARIES = [
     ":compatibility_py",
     ":containers_py",
-    ":cpp_const_py",
     ":cpp_param_py",
     ":cpp_template_py",
     ":deprecation_py",
@@ -473,13 +463,6 @@ drake_py_unittest(
     ],
 )
 
-drake_py_unittest(
-    name = "cpp_const_test",
-    deps = [
-        ":cpp_const_py",
-    ],
-)
-
 drake_py_unittest(
     name = "cpp_param_test",
     deps = [

bindings/pydrake/common/all.py

@@ -1,7 +1,6 @@
 from . import *
 from .compatibility import *
 from .containers import *
-# - `cpp_const` does not offer public Drake symbols.
 # - `cpp_param` does not offer public Drake symbols.
 # - `cpp_template` does not offer public Drake symbols.
 # - `deprecation` does not offer public Drake symbols.