refactor(bazel): shorten Rust toolchain names

MODULE.bazel

@@ -2,7 +2,7 @@ module(name = "alexion", version = "0.1.0")
 
 bazel_dep(name = "rules_rust", version = "0.74.0")
 
-rust = use_extension("//bazel:rust_toolchain.bzl", "rust")
-use_repo(rust, "rust_toolchain")
+rust = use_extension("//bazel:rust.bzl", "rust")
+use_repo(rust, "rust")
 
-register_toolchains("@rust_toolchain//:rust_toolchain")
+register_toolchains("@rust//:rust")

MODULE.bazel.lock

@@ -91,16 +91,16 @@
   },
   "selectedYankedVersions": {},
   "moduleExtensions": {
-    "//bazel:rust_toolchain.bzl%rust": {
+    "//bazel:rust.bzl%rust": {
       "general": {
-        "bzlTransitiveDigest": "WFPDu6Tfd1xmY2gvnknHq77dMzojvViXkLaDJQAq9g0=",
-        "usagesDigest": "SQP3kWaLgKBHOdfxAvAWSUMuSfW8zC/274pBGhq2FlQ=",
+        "bzlTransitiveDigest": "0r4u+74QPphTHEzrdQIFSn4SfNM4AAJNlPyNGE8JwRs=",
+        "usagesDigest": "jJoM2Hp1NbshT//puE4xIUfXdA0K6BRx1WTlsZIKFm4=",
         "recordedFileInputs": {},
         "recordedDirentsInputs": {},
         "envVariables": {},
         "generatedRepoSpecs": {
-          "rust_toolchain": {
-            "bzlFile": "@@//bazel:rust_toolchain.bzl",
+          "rust": {
+            "bzlFile": "@@//bazel:rust.bzl",
             "ruleClassName": "rust_repository",
             "attributes": {}
           }

bazel/BUILD

@@ -1,4 +1,4 @@
 exports_files([
-    "rust_toolchain.bzl",
+    "rust.bzl",
     "utils.bzl",
 ])

bazel/rust.bzl

@@ -126,7 +126,7 @@ rust_stdlib_filegroup(
 load("@rules_rust//rust:toolchain.bzl", "rust_toolchain")
 
 rust_toolchain(
-    name = "rust_toolchain_impl",
+    name = "toolchain_impl",
     rust_doc = ":rustdoc",
     rust_std = ":rust_std",
     rustc = ":rustc",
@@ -153,8 +153,8 @@ rust_toolchain(
 )
 
 toolchain(
-    name = "rust_toolchain",
-    toolchain = ":rust_toolchain_impl",
+    name = "rust",
+    toolchain = ":toolchain_impl",
     toolchain_type = "@rules_rust//rust:toolchain_type",
     visibility = ["//visibility:public"],
 )
@@ -172,7 +172,7 @@ rust_repository = repository_rule(
 
 
 def _rust_impl(module_ctx):
-    rust_repository(name = "rust_toolchain")
+    rust_repository(name = "rust")
 
 
 rust = module_extension(