Catch execution result handler failures, such as parsing issues (#374)

## Summary
<!-- Succinctly describe your change, providing context, what you've
changed, and why. -->

Log an error to the console if handling an execution result fails. This
can happen if something simple like serialization fails when packaging
up the user's response.

## Checklist
<!-- Tick these items off as you progress. -->
<!-- If an item isn't applicable, ideally please strikeout the item by
wrapping it in "~~"" and suffix it with "N/A My reason for skipping
this." -->
<!-- e.g. "- [ ] ~~Added tests~~ N/A Only touches docs" -->

- [ ] ~~Added a [docs PR](https://github.com/inngest/website) that
references this PR~~ N/A
- [ ] ~~Added unit/integration tests~~ N/A
- [x] Added changesets if applicable

.changeset/flat-crabs-drive.md

@@ -0,0 +1,5 @@
+---
+"inngest": patch
+---
+
+Fixed an issue where an error log wasn't shown if execution result parsing failed, such as in the case of serialization failures

packages/inngest/src/components/InngestCommHandler.ts

@@ -753,7 +753,12 @@ export class InngestCommHandler<
           stepOutput.type
         ] as ExecutionResultHandler<ActionResponse>;
 
-        return await handler(stepOutput);
+        try {
+          return await handler(stepOutput);
+        } catch (err) {
+          this.log("error", "Error handling execution result", err);
+          throw err;
+        }
       }
 
       if (method === "GET") {