[Core] The `schemas` context variable has its own page but `database_schemas` does not

### Link to the page(s) on docs.getdbt.com requiring updates

This page has sections for `schemas` and `database_schemas`:
https://docs.getdbt.com/reference/dbt-jinja-functions/on-run-end-context

This page for `schemas` also exists:
https://docs.getdbt.com/reference/dbt-jinja-functions/schemas

But this page does not exist for `database_schemas`:
https://docs.getdbt.com/reference/dbt-jinja-functions/database_schemas

### Tell us more about this update

So to resolve this discrepancy, it seems like either both should have their own page or neither should have their own page.

### Reviewers/Stakeholders/SMEs

DEF (Doug E. Fresh)

### Related GitHub issues

Although not directly related, I noticed this discrepancy when looking at https://github.com/dbt-labs/dbt-core/issues/9600#issuecomment-2007621731 and was researching a context variable that contains the command-line args (which ended up being [`invocation_args_dict`](https://docs.getdbt.com/reference/dbt-jinja-functions/flags#invocation_args_dict)).

### Additional information

_No response_