Investigate usage of scoped labels to simulate MR weights
## Description We want to know how often users use scoped labels as a workaround because MRs cannot have weights assigned. This issue was created as a record for the Teleport request to perform the queries on prod. See internal slack thread for context: https://gitlab.slack.com/archives/C01EMBKS5DW/p1740132731860969 <!-- template sourced from https://gitlab.com/gitlab-org/gitlab/-/blob/master/.gitlab/issue_templates/Default.md -->
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