chore(serializer-gson): Deprecate builder methods that have moved to options

Author: kezz

text-serializer-gson/src/main/java/net/kyori/adventure/text/serializer/gson/GsonComponentSerializer.java

@@ -135,7 +135,9 @@ interface Builder extends AbstractBuilder<GsonComponentSerializer>, Buildable.Bu
      *
      * @return this builder
      * @since 4.0.0
+     * @deprecated for removal since 4.26.0, change the {@link JSONOptions#EMIT_RGB} flag instead
      */
+    @Deprecated
     @Override
     default @NotNull Builder downsampleColors() {
       return this.editOptions(features -> features.value(JSONOptions.EMIT_RGB, false));
@@ -163,6 +165,7 @@ interface Builder extends AbstractBuilder<GsonComponentSerializer>, Buildable.Bu
      * {@inheritDoc}
      *
      * @since 4.0.0
+     * @deprecated for removal since 4.15.0, change the {@link JSONOptions#EMIT_HOVER_EVENT_TYPE} flag instead
      */
     @Deprecated
     @Override