Remove Definition record

Signed-off-by: Matheus Cruz <matheuscruz.dev@gmail.com>

Author: mcruzdev

impl/openapi/src/main/java/io/serverlessworkflow/impl/executors/openapi/UnifiedOpenAPI.java

@@ -192,9 +192,6 @@ public record MediaType(Schema schema) {}
   @JsonIgnoreProperties(ignoreUnknown = true)
   public record Components(Map<String, Schema> schemas) {}
 
-  @JsonIgnoreProperties(ignoreUnknown = true)
-  public record Definitions(Map<String, Schema> definitions) {}
-
   @JsonIgnoreProperties(ignoreUnknown = true)
   public record Schema(
       String type,