Consider removing `slow_db_query_tax_query` and `slow_db_query_meta_query`

### Description

Let me first say I'm biased towards those rules, at least, when it comes to how Alley developers use it. Mainly because I don't think they actually **catch** performance issues beforehand (when we are writing the feature/code). I've yet to see a scenario where they actually helped me to catch slow db queries.

Most of the time, a query is not slow when the feature is built. I'd think Query Monitor and New Relic are more useful tools to find those slow queries. And this rule mostly populate projects with ignores.

See https://github.com/search?q=org%3Aalleyinteractive+phpcs%3Aignore+WordPress.DB.SlowDBQuery.slow_db_query_tax_query&type=code

I also think Alley developers develop with performance in mind, where this rule doesn't take that into account. So this rule is fine for the core ruleset, but it feels out of place for ours.