remove unneeded c8 ignores

Author: robrichard

src/execution/__tests__/flattenAsyncIterable-test.ts

@@ -112,8 +112,6 @@ describe('flattenAsyncIterable', () => {
     let caughtError;
     try {
       await doubles.throw('ouch'); /* c8 ignore start */
-      // Not reachable, always throws
-      /* c8 ignore stop */
     } catch (e) {
       caughtError = e;
     }

src/execution/flattenAsyncIterable.ts

@@ -99,7 +99,6 @@ export function flattenAsyncIterable<T>(
       throw error;
     },
     [Symbol.asyncIterator]() {
-      /* c8 ignore next */
       return this;
     },
   };