Remove uses of `incompatible_use_toolchain_transition`.

Now that Bazel 7.0 has been released, it's time to remove this tech debt.

This has been a no-op since Bazel 5.0, I've been waiting to remove the code for
two years, it's time.

Part of https://github.com/bazelbuild/bazel/issues/14127.

PiperOrigin-RevId: 591940644

protobuf_release.bzl

diff --git a/protobuf_release.bzl b/protobuf_release.bzl
index 327ae9a..a79a303 100644
--- a/protobuf_release.bzl
+++ b/protobuf_release.bzl
@@ -7,44 +7,42 @@
 load(":protobuf_version.bzl", "PROTOC_VERSION")
 
 def _package_naming_impl(ctx):
-  values = {}
-  values["version"] = PROTOC_VERSION
+    values = {}
+    values["version"] = PROTOC_VERSION
 
-  # infer from the current cpp toolchain.
-  toolchain = find_cpp_toolchain(ctx)
-  cpu = toolchain.cpu
-  system_name = toolchain.target_gnu_system_name
+    # infer from the current cpp toolchain.
+    toolchain = find_cpp_toolchain(ctx)
+    cpu = toolchain.cpu
+    system_name = toolchain.target_gnu_system_name
 
-  # rename cpus to match what we want artifacts to be
-  if cpu == "systemz":
-    cpu = "s390_64"
-  elif cpu == "aarch64":
-    cpu = "aarch_64"
-  elif cpu == "ppc64":
-    cpu = "ppcle_64"
+    # rename cpus to match what we want artifacts to be
+    if cpu == "systemz":
+        cpu = "s390_64"
+    elif cpu == "aarch64":
+        cpu = "aarch_64"
+    elif cpu == "ppc64":
+        cpu = "ppcle_64"
 
-  # use the system name to determine the os and then create platform names
-  if "apple" in system_name:
-    values["platform"] = "osx-" + cpu
-  elif "linux" in system_name:
-    values["platform"] = "linux-" + cpu
-  elif "mingw" in system_name:
-    if cpu == "x86_64":
-      values["platform"] = "win64"
+    # use the system name to determine the os and then create platform names
+    if "apple" in system_name:
+        values["platform"] = "osx-" + cpu
+    elif "linux" in system_name:
+        values["platform"] = "linux-" + cpu
+    elif "mingw" in system_name:
+        if cpu == "x86_64":
+            values["platform"] = "win64"
+        else:
+            values["platform"] = "win32"
     else:
-      values["platform"] = "win32"
-  else:
-    values["platform"] = "unknown"
+        values["platform"] = "unknown"
 
-  return PackageVariablesInfo(values = values)
-
+    return PackageVariablesInfo(values = values)
 
 package_naming = rule(
-  implementation = _package_naming_impl,
+    implementation = _package_naming_impl,
     attrs = {
-      # Necessary data dependency for find_cpp_toolchain.
-      "_cc_toolchain": attr.label(default = Label("@bazel_tools//tools/cpp:current_cc_toolchain")),
+        # Necessary data dependency for find_cpp_toolchain.
+        "_cc_toolchain": attr.label(default = Label("@bazel_tools//tools/cpp:current_cc_toolchain")),
     },
     toolchains = ["@bazel_tools//tools/cpp:toolchain_type"],
-    incompatible_use_toolchain_transition = True,
 )

rust/aspects.bzl

diff --git a/rust/aspects.bzl b/rust/aspects.bzl
index a91cede..0399c12 100644
--- a/rust/aspects.bzl
+++ b/rust/aspects.bzl
@@ -327,7 +327,6 @@
             "@rules_rust//rust:toolchain_type",
             "@bazel_tools//tools/cpp:toolchain_type",
         ],
-        incompatible_use_toolchain_transition = True,
     )
 
 rust_upb_proto_library_aspect = _make_proto_library_aspect(is_upb = True)