Use apple constraints over config_setting_group in select (#1563)

The intent of @apple_support//configs:apple is to provide a way for
users to select on whether the current platform is an apple one or not.

It does that by iterating over APPLE_PLATFORMS_CONSTRAINTS, and checking
whether the "cpus" is one of the apple known CPUs. This works in the
general case, but in the exceptional case where the user wants to define
custom apple platforms, it is a problem.

So in this patchset we're switching to using the constraint directly
over the config_setting_group(). It should be a functional no-op for the
general case, but it provides more flexibility if case the user needs a
higher degree of customization.

Author: ma-oli

swift/internal/BUILD

@@ -7,7 +7,7 @@ licenses(["notice"])
 alias(
     name = "swizzle_absolute_xcttestsourcelocation",
     actual = select({
-        "@build_bazel_apple_support//configs:apple": (
+        "@build_bazel_apple_support//constraints:apple": (
             "@build_bazel_apple_support//lib:swizzle_absolute_xcttestsourcelocation"
         ),
         "//conditions:default": ":dummy_swizzle_absolute_xcttestsourcelocation",

tools/worker/BUILD

@@ -75,7 +75,7 @@ cc_library(
         ],
     }),
     data = select({
-        "@build_bazel_apple_support//configs:apple": [
+        "@build_bazel_apple_support//constraints:apple": [
             "@build_bazel_rules_swift_index_import_5_8//:index_import",
             "@build_bazel_rules_swift_index_import_6_1//:index_import",
         ],