[DOCS] Remove `subs="attributes,callouts,macros"` after Asciidoctor migration

Throughout several of our [SQL syntax examples](https://www.elastic.co/guide/en/elasticsearch/reference/current/sql-syntax-select.html), we use the `subs="attributes,callouts,macros"` options with `[source]` snippets.

However, these options aren't needed with Asciidoctor. We should remove them from the Elasticsearch Reference after the Asciidoctor migration is complete.