fix(ci): rename remaining stale @llvm labels to toolchains_llvm_bootstrapped

The root BUILD.bazel, bazel/platforms/release_binaries.bzl,
bazel/rules/testing/wine/wine_runtime.bzl, and rbe.bzl still referenced
@llvm//constraints/libc and @llvm//platforms, which are not visible from
the main repo map (the module is pinned as toolchains_llvm_bootstrapped).
Rename them to the canonical name so analysis of //third_party/v8 pair
targets no longer aborts on '//:local_linux'.

Author: KooshaPari

BUILD.bazel

@@ -9,7 +9,7 @@ platform(
     name = "local_linux",
     constraint_values = [
         # We mark the local platform as glibc-compatible because musl-built rust cannot dlopen proc macros.
-        "@llvm//constraints/libc:gnu.2.28",
+        "@toolchains_llvm_bootstrapped//constraints/libc:gnu.2.28",
     ],
     parents = ["@platforms//host"],
 )

bazel/platforms/release_binaries.bzl

@@ -15,7 +15,7 @@ def multiplatform_binaries(name, platforms = PLATFORMS):
     for platform in platforms:
         platform_data(
             name = name + "_" + platform,
-            platform = "@llvm//platforms:" + platform,
+            platform = "@toolchains_llvm_bootstrapped//platforms:" + platform,
             target = name,
             tags = ["manual"],
         )

bazel/rules/testing/wine/wine_runtime.bzl

@@ -14,7 +14,7 @@ _WINE_RUNTIME_DATA = [
 ]
 
 WINE_TEST_TARGET_COMPATIBLE_WITH = [
-    "@llvm//constraints/libc:gnu.2.28",
+    "@toolchains_llvm_bootstrapped//constraints/libc:gnu.2.28",
     "@platforms//cpu:x86_64",
     "@platforms//os:linux",
 ]

rbe.bzl

@@ -18,7 +18,7 @@ platform(
         "@platforms//cpu:{cpu}",
         "@platforms//os:linux",
         "@bazel_tools//tools/cpp:clang",
-        "@llvm//constraints/libc:gnu.2.28",
+        "@toolchains_llvm_bootstrapped//constraints/libc:gnu.2.28",
     ],
     exec_properties = {{
         # Ubuntu-based image that includes git, python3, dotslash, and other