refactor(core): remove withBody from public testing API (#25171)

PR Close #25171

packages/private/testing/BUILD.bazel

@@ -0,0 +1,16 @@
+package(default_visibility = ["//visibility:public"])
+
+exports_files(["package.json"])
+
+load("//tools:defaults.bzl", "ng_module")
+
+ng_module(
+    name = "testing",
+    srcs = glob(
+        ["**/*.ts"],
+    ),
+    module_name = "@angular/private/testing",
+    deps = [
+        "//packages/core",
+    ],
+)