You could use an Azure Automation account or Azure function (or Azure Logic App) to do what you want.
Look at those solutions to run on a schedule, for example an Azure Automation powershell runbook with a weekly schedule, that checks Azure AD, and then the Azure DevOps API, then emails a report - or delete it.
https://learn.microsoft.com/en-us/azure/automation/overview
https://learn.microsoft.com/en-us/rest/api/azure/devops/account/?view=azure-devops-rest-7.1
https://learn.microsoft.com/en-us/powershell/module/azuread/?view=azureadps-2.0
If your users are accessing Azure DevOps through Azure AD group membership - take a look at Access Review, before you look at creating a custom solution: https://learn.microsoft.com/en-us/azure/active-directory/privileged-identity-management/pim-create-azure-ad-roles-and-resource-roles-review