txt_roll: Return a list of Roll objects

Bug: b/341756093
Change-Id: I25d0df455fa79d96bfabddcdac73fae657d6733c
Reviewed-on: https://pigweed-review.googlesource.com/c/infra/recipes/+/230835
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Presubmit-Verified: CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Danielle Kay <danikay@google.com>
Commit-Queue: Rob Mohr <mohrr@google.com>
diff --git a/recipe_modules/txt_roll/api.py b/recipe_modules/txt_roll/api.py
index d879fb1..12dfb24 100644
--- a/recipe_modules/txt_roll/api.py
+++ b/recipe_modules/txt_roll/api.py
@@ -38,7 +38,7 @@
         self,
         checkout: checkout_api.CheckoutContext,
         txt_entry: TxtEntry,
-    ) -> dict[str, roll_util_api.Roll] | None:
+    ) -> list[roll_util_api.Roll]:
         branch = txt_entry.branch or 'main'
 
         new_revision = self.m.git_roll_util.resolve_new_revision(
@@ -89,17 +89,17 @@
                 old_revision,
                 new_revision,
             )
-            return
+            return []
 
         with self.m.step.nest('txt_path') as pres:
             pres.step_summary_text = repr(txt_entry.path)
 
-        return {
-            txt_entry.path: self.m.roll_util.create_roll(
+        return [
+            self.m.roll_util.create_roll(
                 project_name=txt_entry.path,
                 old_revision=old_revision,
                 new_revision=new_revision,
                 proj_dir=project_dir,
                 direction=direction,
             ),
-        }
+        ]
diff --git a/recipes/txt_roller.py b/recipes/txt_roller.py
index 1c45c7f..ec22503 100644
--- a/recipes/txt_roller.py
+++ b/recipes/txt_roller.py
@@ -70,9 +70,7 @@
     if not rolls:
         return  # pragma: no cover
 
-    authors: Sequence[api.roll_util.Account] = api.roll_util.authors(
-        *rolls.values()
-    )
+    authors: Sequence[api.roll_util.Account] = api.roll_util.authors(*rolls)
 
     author_override: Optional[api.roll_util.Account] = None
     if len(authors) == 1 and props.forge_author:
@@ -83,7 +81,7 @@
     change: api.auto_roller.GerritChange = api.auto_roller.attempt_roll(
         props.auto_roller_options,
         repo_dir=checkout.root,
-        commit_message=api.roll_util.message(*rolls.values()),
+        commit_message=api.roll_util.message(*rolls),
         author_override=author_override,
     )