build: move repeated tsconfig attributes to a macro (#20964)

This helps ensure we use the same tsconfig.json file for all compilations.
Next steps are to make it the same tsconfig.json file used by the editor

PR Close #20964

packages/compiler/testing/BUILD.bazel

@@ -1,13 +1,12 @@
 package(default_visibility = ["//visibility:public"])
 
-load("@build_bazel_rules_typescript//:defs.bzl", "ts_library")
+load("//tools:defaults.bzl", "ts_library")
 
 ts_library(
     name = "testing",
     testonly = 1,
     srcs = glob(["**/*.ts"]),
     module_name = "@angular/compiler/testing",
-    tsconfig = "//packages:tsconfig",
     deps = [
         "//packages:types",
         "//packages/compiler",