Stac-pydantic

- Add optional `numberMatched` and `numberReturned` to `api.collections.Collections` model to match the OGC Common part2 specification

- Add more **MimeTypes** (geojsonseq, pbf, mvt, ndjson, openapi_yaml, pdf, csv, parquet)

- Cache remote JSON schemas for extensions (155, avbentem)
- add `requests` and `jsonschema` in a **validation** optional dependencies (156, vincentsarago)

- Allow extra fields in Links (144, jonhealy1)
- Remove the deprecated `Context` extension (138, vincentsarago)
- Rename `stac_pydantic.api.conformance.ConformanceClasses` to `stac_pydantic.api.conformance.Conformance`
- Update pre-commit configuration and switch to astral-sh/ruff for linter and formater
- Add official support for python 3.12
- Enforce required `type` key for `Collection` and `Catalog` models
- Add queryables link relation type (123, constantinius)
- Fix STAC API Query Extension operator names from ne->neq, le->lte, and ge->gte (120, philvarner)
- Better **datetime** parsing/validation by using Pydantic native types and remove `ciso8601` requirement (131, eseglem)
- move datetime validation in `StacCommonMetadata` model definition (131, eseglem)
- use `StacBaseModel` as base model for `Asset` model (148, vincentsarago)
- add `license` in `StacCommonMetadata` model (147, vincentsarago)
- make `limit` optional in `api.Search` model (150, vincentsarago)
- set `start/end datetime` to the datetime value when passing only one value in `api.Search` (152, vincentsarago)

- Support pydantic>2.0 (huard)

- Allow item bbox to be null if item geometry is null (108, yellowcap)
- Include 'children' link relation (112, moradology)