Update builder methods visibility to public (#2506)

Author: yefrig

smithy-aws-traits/src/main/java/software/amazon/smithy/aws/traits/tagging/TaggableApiConfig.java

@@ -117,22 +117,22 @@ public static final class Builder implements SmithyBuilder<TaggableApiConfig> {
         private ShapeId listTagsApi;
         private SourceLocation sourceLocation = SourceLocation.none();
 
-        Builder tagApi(ShapeId tagApi) {
+        public Builder tagApi(ShapeId tagApi) {
             this.tagApi = tagApi;
             return this;
         }
 
-        Builder untagApi(ShapeId untagApi) {
+        public Builder untagApi(ShapeId untagApi) {
             this.untagApi = untagApi;
             return this;
         }
 
-        Builder listTagsApi(ShapeId listTagsApi) {
+        public Builder listTagsApi(ShapeId listTagsApi) {
             this.listTagsApi = listTagsApi;
             return this;
         }
 
-        Builder sourceLocation(SourceLocation sourceLocation) {
+        public Builder sourceLocation(SourceLocation sourceLocation) {
             this.sourceLocation = sourceLocation;
             return this;
         }