Check that skills are relevant for all adapters

### Description

Seeing this comment https://github.com/dbt-labs/llm-skills/blob/b57f4dd49759b5352aa45a94b642dc3600269555/dbt-commands/writing-data-tests/SKILL.md?plain=1#L141

I think that we need to be cautious about some recommendations that could apply to some adapters but not all.

In this case, for BigQuery a `max` would still scan the entire table (and potentially cost thousands of $)

- we should review that skills apply to all adapters ; and in case they don't add this information to the skills
- we should maybe add skills dedicated to some adapters to mention the best practices -- e.g.
- on BQ, we likely don't want to call `dbt show` with a `where` if there is no partition in the model
- on Snowflake, the metadata queries are "free" and we can have quite a few