feat: update API to latest incidentio OpenAPI V3 spec

[maxtacu]

A generated client copy from updated openapi definition: https://api.incident.io/v1/openapiV3.json
No AI slop here. Simply updated the endpoint of the openapi definition and executed

poetry install
make download
make generate

I also removed the incident_io_openapi.json because the new one includes examples of token values and github identifies it as a secret leak, thus blocking the push. Also gitguardian would fail the same way.

Client currently fails retrieving catalog types because incidentio introduced a new incident-template enum value to the icon response property in GET /v2/catalog_entries, GET /v2/catalog_entries/{id} and 14 more. see the changelog here: https://docs.incident.io/api-reference/changelog#27-august-2026