Rollup merge of #85297 - infinity0:master, r=Mark-Simulacrum

bootstrap: build cargo only if requested in tools

In Debian we'd like to build rustfmt and clippy alongside rustc, but we're still excluding cargo from the rustc build and doing that separately. This patch makes that possible.

src/bootstrap/tool.rs

@@ -593,7 +593,14 @@ impl Step for Cargo {
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
         let builder = run.builder;
-        run.path("src/tools/cargo").default_condition(builder.config.extended)
+        run.path("src/tools/cargo").default_condition(
+            builder.config.extended
+                && builder.config.tools.as_ref().map_or(
+                    true,
+                    // If `tools` is set, search list for this tool.
+                    |tools| tools.iter().any(|tool| tool == "cargo"),
+                ),
+        )
     }
 
     fn make_run(run: RunConfig<'_>) {