Fixes the schema and docs to make the error.instance property optional to authors

Signed-off-by: Charles d'Avernas <[email protected]>

Author: cdavernas

dsl-reference.md

@@ -1451,7 +1451,7 @@ Defines the [Problem Details RFC](https://datatracker.ietf.org/doc/html/rfc7807)
 |----------|:----:|:--------:|-------------|
 | type | [`uri-template`](#uri-template) | `yes` | A URI reference that identifies the [`error`](#error) type. <br><u>For cross-compatibility concerns, it is strongly recommended to use [Standard Error Types](#standard-error-types) whenever possible.<u><br><u>Runtimes **MUST** ensure that the property has been set when raising or escalating the [`error`](#error).<u> |
 | status | `integer` | `yes` | The status code generated by the origin for this occurrence of the [`error`](#error).<br><u>For cross-compatibility concerns, it is strongly recommended to use [HTTP Status Codes](https://datatracker.ietf.org/doc/html/rfc7231#section-6) whenever possible.<u><br><u>Runtimes **MUST** ensure that the property has been set when raising or escalating the [`error`](#error).<u> |
-| instance | `string` | `yes` | A [JSON Pointer](https://datatracker.ietf.org/doc/html/rfc6901) used to reference the component the [`error`](#error) originates from.<br><u>Runtimes **MUST** set the property when raising or escalating the [`error`](#error). Otherwise ignore.<u> |
+| instance | `string` | `no` | A [JSON Pointer](https://datatracker.ietf.org/doc/html/rfc6901) used to reference the component the [`error`](#error) originates from.<br><u>Runtimes **MUST** set the property when raising or escalating the [`error`](#error). Otherwise ignore.<u> |
 | title | `string` | `no` | A short, human-readable summary of the [`error`](#error). |
 | detail | `string` | `no` | A human-readable explanation specific to this occurrence of the [`error`](#error). |
 

schema/workflow.yaml

@@ -1098,7 +1098,7 @@ $defs:
         type: string
         title: ErrorDetails
         description: A human-readable explanation specific to this occurrence of the error.
-    required: [ type, status, instance ]
+    required: [ type, status ]
   endpoint:
     title: Endpoint
     description: Represents an endpoint.