fix(inngest): add JsonError export from types (#687)

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

Added an export for `JsonError` type to `index.ts` from `types`.


## 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 bug fix
- [ ] ~~Added unit/integration tests~~ N/A only touches types
- [x] Added changesets if applicable

## Related
Fixes #686

---------

Co-authored-by: Jack Williams <1736957+jpwilliams@users.noreply.github.com>
Co-authored-by: Jack Williams <jack@inngest.com>

.changeset/wise-knives-argue.md

@@ -0,0 +1,5 @@
+---
+"inngest": patch
+---
+
+Add exports for `JsonError` type to fix a TypeScript error when using Inngest in projects with `composite` setting in `tsconfig`.

packages/inngest/src/index.ts

@@ -91,6 +91,7 @@ export type {
   FailureEventPayload,
   FinishedEventPayload,
   Handler,
+  JsonError,
   LogLevel,
   OutgoingOp,
   RegisterOptions,

packages/inngest/test/composite_project/src/index.ts

@@ -1,5 +1,8 @@
 import * as Inngest from "inngest";
 
+// Prove certain types are exported and can be used
+type CatchAll = Inngest.JsonError;
+
 export const inngest = new Inngest.Inngest({
   id: "me",
   schemas: new Inngest.EventSchemas().fromRecord<{