fix typo

Summary: per title

Reviewed By: JakobDegen

Differential Revision: D69204099

fbshipit-source-id: f66e893cd26fa7a32c43a248db26d289aedccc0b

Author: Jeremy Braun

starlark/src/tests/uncategorized.rs

@@ -172,7 +172,7 @@ def loop():
         if len(xs) == 3:
             xs.append(4)
 loop()"#,
-        "mutate an iterable",
+        "mutates an iterable",
     );
 }
 
@@ -272,7 +272,7 @@ def foo():
         break
 foo()
 "#,
-        "mutate an iterable",
+        "mutates an iterable",
     );
     assert::fail(
         r#"

starlark/src/values/error.rs

@@ -54,7 +54,7 @@ pub enum ValueError {
     KeyNotFound(String),
     #[error("Immutable")]
     CannotMutateImmutableValue,
-    #[error("This operation mutate an iterable for an iterator while iterating.")]
+    #[error("This operation mutates an iterable for an iterator while iterating.")]
     MutationDuringIteration,
     #[error("Object of type `{0}` has no attribute `{1}`")]
     NoAttr(String, String),