Write ExecutableAndOptionsProto records uncompressed.

`serialized_executable` is already a snappy-compressed split
`GpuExecutableProto` (see `WriteSplitGpuExecutable`). Compressing the outer
container again saves no space (dropping it adds 0.06% on a 330 MB
executable), but it costs an extra compression pass on write and a full
decompression pass on load.

Riegeli stores the compression type per chunk, so readers don't change and
existing artifacts still load.

Alternative considered: leave the inner proto uncompressed and compress the
outer one instead. That would mean deciding per use case when to skip
compression, which adds logic for little gain, since the outer proto is
small apart from `serialized_executable`.

PiperOrigin-RevId: 987497408

third_party/xla/xla/util/split_proto/split_executable_and_options_writer.cc

@@ -78,8 +78,13 @@ ExecutableAndOptionsProto GetProtoWithoutSerializedExecutable(
 absl::Status WriteSplitExecutableAndOptions(
     const ExecutableAndOptionsProto& executable_and_options,
     std::unique_ptr<riegeli::Writer> writer) {
-  riegeli::RecordWriter record_writer(std::move(writer),
-                                      GetGpuSplitProtoOptions());
+  riegeli::RecordWriter record_writer(
+      std::move(writer),
+      // The bulk of this proto is `serialized_executable`, which is already a
+      // compressed split proto. Compressing it again does not reduce the size
+      // but adds a full (de)compression pass over the whole executable when
+      // serializing and when loading it.
+      GetSplitProtoRiegeliOptions(SplitProtoCompression::kNone));
   SplitProtoManifest manifest = BuildManifest();
   TF_RETURN_WITH_CONTEXT_IF_ERROR(
       WriteRecord(record_writer, manifest),