Ensure OpenAPI specs can serve as a reliable source of truth for typed client generation

[vdusek]

Fix and consolidate the existing OpenAPI specifications to reflect the actual API behavior, ensuring they can serve as a source of truth for typed API client generation.

For additional context, see parent (epic) issue - https://github.com/apify/apify-core/issues/25186.

All PRs:

• fix(openapi): Fix OpenApi specification #2169
• ci(openapi): Add spell-check CI step and fix existing typos #2187
• chore(openapi): Update to Open API v3.1.2 #2188
• ci(openapi): Improve OpenAPI checks #2190
• fix(openapi): Fix all OpenAPI linting errors and add stricter validation rules #2194
• fix(openapi): Add format specs and constraints to schema fields #2195
• fix(openapi): Standardize OpenAPI schemas and fix API response types #2212