Update to NDC Spec v0.2.0-rc.1 (#38)

This PR updates the version of NDC Spec used by the SDK to v0.2.0-rc.1.
This is mostly just a types change, but there's also the addition of
logic that checks the `X-Hasura-NDC-Version` incoming header as per the
spec.

.github/workflows/release.yaml

@@ -11,6 +11,8 @@ jobs:
     if: ${{ startsWith(github.ref, 'refs/tags/v') }}
 
     steps:
+      - uses: actions/checkout@v4
+
       - name: Get version from tag
         id: get-version
         run: |

CHANGELOG.md

@@ -6,9 +6,16 @@ This changelog documents the changes between release versions.
 
 Changes to be included in the next upcoming release
 
+**Breaking changes** ([#38](https://github.com/hasura/ndc-sdk-rs/pull/38)):
+
+- Updated to support [v0.2.0 of the NDC Spec](https://hasura.github.io/ndc-spec/specification/changelog.html#020). This is a very large update which adds new features and some breaking changes.
+- If the [`X-Hasura-NDC-Version`](https://hasura.github.io/ndc-spec/specification/versioning.html) header is sent, the SDK will validate that the connector supports the incoming request's version and reject it if it does not. If no header is sent, no action is taken.
+
 ## [0.5.0] - 2024-10-29
 
-- add utilities to [implement PrintSchemaAndCapabilities](https://github.com/hasura/ndc-sdk-rs/pull/34). This splits the sdk into multiple crates to avoid bringing in openssl
+- A default request size limit of 100MB was added. This can be overridden with the `HASURA_MAX_REQUEST_SIZE` environment variable ([#29](https://github.com/hasura/ndc-sdk-rs/pull/29)).
+- Connector state is now only initialized on the first request that actually uses it. This means `/capabilities`, `/schema` and `/health` can be used even if state initialization would otherwise fail ([#31](https://github.com/hasura/ndc-sdk-rs/pull/31)).
+- Add utilities to [implement PrintSchemaAndCapabilities](https://github.com/hasura/ndc-sdk-rs/pull/34). This splits the sdk into multiple crates to avoid bringing in openssl
 
 ## [0.4.0] - 2024-08-30