fix copying default privs for blue/green (#32086)

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fix copying default privs for blue/green deployment when the grantee is
PUBLIC
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blue/green deployments break when there is a default priv with the
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Author: josharenberg

misc/dbt-materialize/dbt/include/materialize/macros/deploy/deploy_init.sql

@@ -165,7 +165,10 @@ SELECT
   'IN SCHEMA {{ to }} '         ||
   'GRANT '  || privilege_type   || ' ' ||
   'ON '     || object_type      || 's ' ||
-  'TO '     || quote_ident(grantee)
+  CASE
+    WHEN grantee = 'PUBLIC' THEN 'TO PUBLIC'
+    ELSE 'TO '     || quote_ident(grantee)
+  END
 FROM mz_internal.mz_show_default_privileges
 WHERE database = current_database() AND schema = {{ dbt.string_literal(from) }}
     AND object_owner <> 'none' AND grantee <> 'none'