Add --incompatible_use_platforms_repo_for_constraints

This change adds an incompatible flag to disable constrains bundled with Bazel
in @bazel_tools.

Incompatible change issue:
https://github.com/bazelbuild/bazel/issues/8622

Tracking issue:
https://github.com/bazelbuild/bazel/issues/6516

RELNOTES: Incompatible change `--incompatible_use_platforms_repo_for_constraints` has been added. See https://github.com/bazelbuild/bazel/issues/8622 for details.

Closes #8625.

This is encore of https://github.com/bazelbuild/bazel/commit/332379ad6f8c49b0e087b504d73d3483c529e399. Previous implementation failed with dependency cycle with the configuration. In this attempt I don't use selects, but I've put the incompatible flag checking logic directly into the alias rule. Not nice, but get's thing done.

RELNOTES:
PiperOrigin-RevId: 254357477
diff --git a/tools/cpp/BUILD.static.freebsd b/tools/cpp/BUILD.static.freebsd
index 5dd2a8e..b21dc3d 100644
--- a/tools/cpp/BUILD.static.freebsd
+++ b/tools/cpp/BUILD.static.freebsd
@@ -62,12 +62,12 @@
 toolchain(
     name = "cc-toolchain-freebsd",
     exec_compatible_with = [
-        "@bazel_tools//platforms:x86_64",
-        "@bazel_tools//platforms:freebsd",
+        "@platforms//cpu:x86_64",
+        "@platforms//os:freebsd",
     ],
     target_compatible_with = [
-        "@bazel_tools//platforms:x86_64",
-        "@bazel_tools//platforms:freebsd",
+        "@platforms//cpu:x86_64",
+        "@platforms//os:freebsd",
     ],
     toolchain = ":cc-compiler-freebsd",
     toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",
@@ -97,11 +97,11 @@
 toolchain(
     name = "cc-toolchain-armeabi-v7a",
     exec_compatible_with = [
-        "@bazel_tools//platforms:arm",
+        "@platforms//cpu:arm",
     ],
     target_compatible_with = [
-        "@bazel_tools//platforms:arm",
-        "@bazel_tools//platforms:android",
+        "@platforms//cpu:arm",
+        "@platforms//os:android",
     ],
     toolchain = ":cc-compiler-armeabi-v7a",
     toolchain_type = "@bazel_tools//tools/cpp:toolchain_type",