Revert "Auto merge of #105058 - Nilstrieb:no-merge-commits-for-you-only-bors-is-allowed-to-do-that, r=jyn514"

This reverts commit 4839886f0a, reversing
changes made to ce85c98575.

src/bootstrap/native.rs

@@ -24,8 +24,6 @@ use crate::util::get_clang_cl_resource_dir;
 use crate::util::{self, exe, output, t, up_to_date};
 use crate::{CLang, GitRepo};
 
-use build_helper::ci::CiEnv;
-
 #[derive(Clone)]
 pub struct LlvmResult {
     /// Path to llvm-config binary.
@@ -219,7 +217,7 @@ pub(crate) fn is_ci_llvm_available(config: &Config, asserts: bool) -> bool {
         return false;
     }
 
-    if CiEnv::is_ci() {
+    if crate::util::CiEnv::is_ci() {
         // We assume we have access to git, so it's okay to unconditionally pass
         // `true` here.
         let llvm_sha = detect_llvm_sha(config, true);