[cast] Remove cast_sys_info and cast_sys_info_shlib targets.

Remove the all-in-one CreateSysInfo() targets.

Bug: b/130731732
Change-Id: I83bd36bd625a4a736ff1e25b1bc09555ed34cff8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1583422
Commit-Queue: Wez <wez@chromium.org>
Reviewed-by: Luke Halliwell <halliwell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#657669}

chromecast/base/BUILD.gn

@@ -303,27 +303,6 @@ group("default_create_sys_info") {
   }
 }
 
-# TODO(b/130731732): Remove these targets once dependents are all migrated.
-group("cast_sys_info") {
-  public_deps = [
-    ":cast_sys_info_util",
-    ":dummy_cast_sys_info",
-  ]
-  if (is_android || chromecast_branding == "public") {
-    public_deps += [ ":default_create_sys_info" ]
-  }
-}
-group("cast_sys_info_shlib") {
-  if (!is_android) {
-    deps = [
-      ":shlib_create_sys_info",
-    ]
-    public_deps = [
-      ":dummy_cast_sys_info",
-    ]
-  }
-}
-
 cast_source_set("thread_health_checker") {
   sources = [
     "thread_health_checker.cc",