Event payload json parsing error should be non-retriable error

[djfarrelly]

Describe the bug
If the Go SDK cannot parse the incoming event JSON correctly, an error is thrown and is retried until the function is considered failed.

To Reproduce

1. Define an event payload with time.Time as the struct field type
2. Send an event with an un parseable value for this, e.g. 2024-07-01
3. There should be an error unmarshalling event for function error

Expected behavior
I would expect event payload parsing errors to not be retried as the event payload doesn't change across retries, each retry would fail.

This should tell the Inngest executor to not retry this event similar to the TS SDK's "Non Retriable error"

Code snippets / Logs / Screenshots

System info (please complete the following information):

github.com/inngest/inngestgo v0.4.3-0.20230710181215-c7670fdb9b07

Additional context
n/a