fix: Update orval configuration for handling JSON examples in prompt registry specification

[KavithaSiva]

Context

Updates orval config to ignore linting issues with JSON examples in spec.

With recent updates to prompt registry spec: https://github.tools.sap/AI/prompt-registry/pull/310 the SDK generation step was failing.

Reason is we use orval in the post generation step to generate zod schemas, and one of the descriptions in the spec file:

This selector allows you to define the scope of translation, such as specific placeholders or messages with specific roles. For example, `{"category": "placeholders", "items": ["user_input"], "source_language": "de-DE"}` targets the value of "user_input" in `placeholder_values` specified in the request payload; and considers the value to be in German.

uses double quotes in the JSON example which is escaped using \ by orval leading to linting errors.
As this lint rule severity is low, I decided to ignore the rule instead.

[davidkna-sap]

In #1293 I added it to the eslint config, but this should be fine too and a bit more targeted.