[Schema Inaccuracy] dismissal request and bypass request webhooks have no required fields

Start in descriptions/ghec/ghec.json and inspect the listed exemption, dismissal-request, and bypass-request schema components. Determine which properties are non-optional in the webhook payloads, add those properties to each component's required section, and verify that the resulting schemas produce accurate TypeScript webhook types.

Schema Inaccuracy

The following schema components do not define any required fields, even though some fields are always present (e.g. primary keys):

• exemption-request
• exemption-response
• dismissal-request-code-scanning-metadata
• dismissal-request-secret-scanning-metadata
• exemption-request-secret-scanning-metadata
• dismissal-request-code-scanning
• dismissal-request-secret-scanning
• exemption-request-secret-scanning
• exemption-request-push-ruleset-bypass

These components are used by the various bypass-request and dismissal-request webhooks, such as:

• dismissal-request-secret-scanning-cancelled
• dismissal-request-secret-scanning-completed
• dismissal-request-secret-scanning-created
• dismissal-request-secret-scanning-response-dismissed
• dismissal-request-secret-scanning-response-submitted
• dismissal-request-code-scanning-created
• dismissal-request-code-scanning-response-submitted
• bypass-request-secret-scanning-cancelled
• bypass-request-secret-scanning-completed
• bypass-request-secret-scanning-created
• bypass-request-secret-scanning-response-dismissed
• bypass-request-secret-scanning-response-submitted
• bypass-request-push-ruleset-cancelled
• bypass-request-push-ruleset-completed
• bypass-request-push-ruleset-created
• bypass-request-push-ruleset-response-dismissed
• bypass-request-push-ruleset-response-submitted

Expected

The schemas of the dismissal request and bypass request webhooks should have all non-optional fields listed in required sections of their schema components.

For example, most of the fields of exemption-request are likely non-optional in GitHub's implementation: id (primary key), number (alternate key), repository_id (a request needs a repository), requester_login (a user needs to create the request), request_type, status, created_at, html_url. I don't know the exact values since it would be specific to the GitHub database and implementation.

Reproduction Steps

None - observed by reviewing https://raw.githubusercontent.com/github/rest-api-description/refs/heads/main/descriptions/ghec/ghec.json and trying to use @octokit/openapi-webhooks-types-ghec (which depends on the schema data) in TypeScript.