fix: add missing column in group by expression

when trying to use the lsp server autocompletion didnt work and when
activating logs found messages such as:

> ERROR pgt_lsp::session error=Database error: column "c.relkind" must appear in the GROUP BY clause or be used in an aggregate function

upon adding c.relkind into the group by expression autocomplete started
working as expected

Author: Nicolás De los Santos

crates/pgt_schema_cache/src/queries/tables.sql

@@ -35,7 +35,8 @@ where
 group by
   c.oid,
   c.relname,
+  c.relkind,
   c.relrowsecurity,
   c.relforcerowsecurity,
   c.relreplident,
-  nc.nspname;
+  nc.nspname;