When using CodeQL, what extension stores query suite definitions?

Query suite definitions in CodeQL are stored using the .qls file extension. A query suite defines a collection of queries to be run during an analysis and allows for grouping them based on categories like language, security relevance, or custom filters.

In contrast:

.ql files are individual queries.

.qll files are libraries used by .ql queries.

.yml is used for workflows, not query suites.