build: remove rust dependencies (kythe#6069)

.gitignore

@@ -34,10 +34,6 @@ tools/node
 # User bazelrc overrides
 /user.bazelrc
 
-# Ignore Rust build artifacts
-kythe/rust/**/target
-rust-project.json
-
 ### Added by Hedron's Bazel Compile Commands Extractor: https://github.com/hedronvision/bazel-compile-commands-extractor
 # The external link: Differs on Windows vs macOS/Linux, so we can't check it in. The pattern needs to not have a trailing / because it's a symlink on macOS/Linux.
 /external

BUILD

@@ -1,7 +1,6 @@
 load("@bazel_skylib//:bzl_library.bzl", "bzl_library")
 load("//:version.bzl", "MAX_VERSION", "MIN_VERSION")
 load("@bazel_gazelle//:def.bzl", "gazelle")
-load("@rules_rust//proto/protobuf:toolchain.bzl", "rust_proto_toolchain")
 load("@hedron_compile_commands//:refresh_compile_commands.bzl", "refresh_compile_commands")
 
 package(default_visibility = ["//visibility:private"])
@@ -38,7 +37,6 @@ sh_test(
 # gazelle:exclude **/examples/
 # gazelle:exclude **/testdata/
 # gazelle:exclude **/*_go_proto/
-# gazelle:exclude **/*_rust_proto/
 # gazelle:prefix kythe.io
 # gazelle:map_kind go_binary go_binary //tools:build_rules/shims.bzl
 # gazelle:map_kind go_library go_library //tools:build_rules/shims.bzl
@@ -78,20 +76,6 @@ bzl_library(
     srcs = ["setup.bzl"],
 )
 
-# Create a Rust protobuf toolchain with protobuf version 2.8.2
-rust_proto_toolchain(
-    name = "rust_proto_toolchain_impl",
-    edition = "2021",
-    proto_compile_deps = ["@crate_index//:protobuf"],
-    proto_plugin = "@crate_index//:protobuf-codegen__protoc-gen-rust",
-)
-
-toolchain(
-    name = "rust_proto_toolchain",
-    toolchain = ":rust_proto_toolchain_impl",
-    toolchain_type = "@rules_rust//proto/protobuf:toolchain_type",
-)
-
 refresh_compile_commands(
     name = "refresh_compile_commands",
     # Gathering header compile commands fails due to mismatched clang versions with RBE.

WORKSPACE

@@ -87,38 +87,6 @@ ruby_bundle(
     gemfile_lock = "//kythe/web/site:Gemfile.lock",
 )
 
-load("@rules_rust//crate_universe:defs.bzl", "crate", "crates_repository", "render_config")
-
-# Run `CARGO_BAZEL_REPIN=1 bazel sync --only=crate_index` after updating
-crates_repository(
-    name = "crate_index",
-    annotations = {
-        "protobuf-codegen": [crate.annotation(gen_binaries = True)],
-    },
-    cargo_lockfile = "//:Cargo.Bazel.lock",
-    lockfile = "//:cargo-bazel-lock.json",
-    packages = {
-        # Dependencies for our Rust protobuf toolchain
-        "protobuf": crate.spec(
-            features = ["with-bytes"],
-            version = "=2.28.0",
-        ),
-        "protobuf-codegen": crate.spec(
-            version = "=2.28.0",
-        ),
-    },
-    rust_version = "1.71.1",
-)
-
-load("@crate_index//:defs.bzl", "crate_repositories")
-
-crate_repositories()
-
-# Register our Rust protobuf toolchain from the BUILD file
-register_toolchains(
-    ":rust_proto_toolchain",
-)
-
 http_archive(
     name = "aspect_bazel_lib",
     sha256 = "d488d8ecca98a4042442a4ae5f1ab0b614f896c0ebf6e3eafff363bcc51c6e62",