Remove unnecessary rpath special handling on macOS

Based on
bazelbuild/bazel#10254 (comment)
and bazelbuild/bazel#12304 being fixed, this
special handling of rpaths on macOS appears to be unnecessary.

This cleanup ensures that Bazel sets the correct metadata for the exec
location of Go libraries linked in c-shared mode, which in turn allows
to not include them in the runfiles of all dependents - cc_* targets
depending on them will now generate the correct rpath entries to find
the libraries at runtime at the usual position.

go/private/actions/link.bzl

@@ -20,7 +20,6 @@ load(
 )
 load(
     "//go/private:mode.bzl",
-    "LINKMODE_C_SHARED",
     "LINKMODE_NORMAL",
     "LINKMODE_PLUGIN",
     "extld_from_cc_toolchain",
@@ -108,13 +107,6 @@ def emit_link(
     if go.mode.link == LINKMODE_PLUGIN:
         tool_args.add("-pluginpath", archive.data.importpath)
 
-    # TODO: Rework when https://github.com/bazelbuild/bazel/pull/12304 is mainstream
-    if go.mode.link == LINKMODE_C_SHARED and (go.mode.goos in ["darwin", "ios"]):
-        extldflags.extend([
-            "-install_name",
-            rpath.install_name(executable),
-        ])
-
     arcs = _transitive_archives_without_test_archives(archive, test_archives)
     arcs.extend(test_archives)
     if (go.coverage_enabled and go.coverdata and

go/private/rules/binary.bzl

@@ -40,10 +40,6 @@ load(
     "LINKMODE_PLUGIN",
     "LINKMODE_SHARED",
 )
-load(
-    "//go/private:rpath.bzl",
-    "rpath",
-)
 
 _EMPTY_DEPSET = depset([])
 
@@ -69,8 +65,6 @@ def new_cc_import(
         static_library = None,
         alwayslink = False,
         linkopts = []):
-    if dynamic_library:
-        linkopts = linkopts + rpath.flags(go, dynamic_library)
     return CcInfo(
         compilation_context = cc_common.create_compilation_context(
             defines = defines,