Update incorrect comment

Author: bjorn3

src/bootstrap/src/core/metadata.rs

@@ -86,7 +86,7 @@ fn workspace_members(build: &Build) -> Vec<Package> {
         packages
     };
 
-    // Collects `metadata.packages` from all workspaces.
+    // Collects `metadata.packages` from the root and library workspaces.
     let mut packages = vec![];
     packages.extend(collect_metadata("Cargo.toml"));
     packages.extend(collect_metadata("library/Cargo.toml"));