✨ Add support for OpenAPI 3.1.0 (#9770)
* ✨ Update OpenAPI models for JSON Schema 2020-12 and OpenAPI 3.1.0
* ✨ Add support for summary and webhooks
* ✨ Update JSON Schema for UploadFiles
* ⏪️ Revert making paths optional, to ensure always correctness
* ⏪️ Keep UploadFile as format: binary for compatibility with the rest of Pydantic bytes fields in v1
* ✨ Update version of OpenAPI generated to 3.1.0
* ✨ Update the version of Swagger UI
* 📝 Update docs about extending OpenAPI
* 📝 Update docs and links to refer to OpenAPI 3.1.0
* ✨ Update logic for handling webhooks
* ♻️ Update parameter functions and classes, deprecate example and make examples the main field
* ✅ Update tests for OpenAPI 3.1.0
* 📝 Update examples for OpenAPI metadata
* ✅ Add and update tests for OpenAPI metadata
* 📝 Add source example for webhooks
* 📝 Update docs for metadata
* 📝 Update docs for Schema extra
* 📝 Add docs for webhooks
* 🔧 Add webhooks docs to MkDocs
* ✅ Update tests for extending OpenAPI
* ✅ Add tests for webhooks
* ♻️ Refactor generation of OpenAPI and JSON Schema with params
* 📝 Update source examples for field examples
* ✅ Update tests for examples
* ➕ Make sure the minimum version of typing-extensions installed has deprecated() (already a dependency of Pydantic)
* ✏️ Fix typo in Webhooks example code
* 🔥 Remove commented out code of removed nullable field
* 🗑️ Add deprecation warnings for example argument
* ✅ Update tests to check for deprecation warnings
* ✅ Add test for webhooks with security schemes, for coverage
* 🍱 Update image for metadata, with new summary
* 🍱 Add docs image for Webhooks
* 📝 Update docs for webhooks, add docs UI image
