build: Switch from attrs to dataclasses

Change-Id: I666b744f741aec290d3cfcb01812c336e73fc099
Reviewed-on: https://pigweed-review.googlesource.com/c/infra/recipes/+/160191
Reviewed-by: Armando Montanez <amontanez@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed-service-accounts.iam.gserviceaccount.com>
Pigweed-Auto-Submit: Rob Mohr <mohrr@google.com>
diff --git a/recipe_modules/build/api.py b/recipe_modules/build/api.py
index 0473553..9f70f47 100644
--- a/recipe_modules/build/api.py
+++ b/recipe_modules/build/api.py
@@ -13,16 +13,19 @@
 # the License.
 """Calls to build code."""
 
-import attr
+import dataclasses
+from typing import Any
+
+from PB.recipe_modules.pigweed.build import options as options_pb2
 from recipe_engine import recipe_api
 
 
-@attr.s
+@dataclasses.dataclass
 class Context:
-    _api = attr.ib()
-    checkout_root = attr.ib()
-    root = attr.ib()
-    options = attr.ib()
+    _api: Any
+    checkout_root: Any
+    root: Any
+    options: options_pb2.Options
 
 
 class BuildApi(recipe_api.RecipeApi):