Bug: openapi schema, rekorLogId should be nullable

[HuakunShen]

I am using the openapi schema (https://api.jsr.io/.well-known/openapi) to generate client.
And I noticed an error in the schema

Here is the schema for rekorLogId

rekorLogId:
          type: string
          description: Rekor log ID for the published package version.

But when a package isn't signed by github action, its rekorLogId is null.
I believe a nullable: true should be added to the schema.

[lucacasonato]

We'd welcome a PR to the schema here: https://github.com/jsr-io/jsr/blob/main/api/src/api.yml