fix: make enums case-insensitive so that the hangar publish plugin can be used with groovy

backend/src/main/java/io/papermc/hangar/config/jackson/JacksonConfig.java

@@ -0,0 +1,21 @@
+package io.papermc.hangar.config.jackson;
+
+import com.fasterxml.jackson.databind.MapperFeature;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Primary;
+import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;
+
+@Configuration
+public class JacksonConfig {
+
+    @Bean
+    @Primary
+    ObjectMapper jacksonObjectMapper(final Jackson2ObjectMapperBuilder builder) {
+        return builder
+            .createXmlMapper(false)
+            .featuresToEnable(MapperFeature.ACCEPT_CASE_INSENSITIVE_ENUMS)
+            .build();
+    }
+}