Automating Apex Test Execution

Hello Community,

I am looking to Automate the Apex test execution/ Automatically running the test classes on a schedule basis, for example, once in every week. I cannot find a way in Salesforce to do that, I know Gearset has this possibility, but anyone knows if it can be achieved without using any 3rd party app ? Like may be writing a trigger or flow to automate this.

Any suggestions would be appreciated.