Update YAML import version in OpenAPI and add license field in deno.json

Author: GroophyLifefor

deno.json

@@ -10,5 +10,6 @@
   },
   "imports": {
     "@eemeli/yaml": "jsr:@eemeli/yaml@^2.7.1"
-  }
+  },
+  "license": "MIT"
 }

src/OpenAPI.ts

@@ -18,7 +18,7 @@ import type {
   OpenAPISecurityScheme,
   SecurityRequirement,
 } from "./OpenAPI.types.ts";
-import { stringify } from "jsr:@eemeli/yaml";
+import { stringify } from "jsr:@eemeli/yaml@2.7.1";
 
 class OpenAPI {
   readonly _openAPI: OpenAPIDoc;