It will be good to add more commentary here to the next person adding
a test, and mention
that only stable values should be included in this view. what do you think?

I added a comment, but I don't think a test writer would be confused for long if they did break that rule.

+ (references <link
linkend="catalog-pg-class"><structname>pg_statistic_ext</structname></link>.<structfield>stxrelid</structfield>)

Fixed catalog-pg-attribute and catalog-pg-statistic-ext