Possible reasons for Salesforce Sharing Lock Exception:

“The sharing calculation you requested can’t be processed right now, because it interferes with another operation already in progress. Please try again later.” are

1. Simultaneously inserting a custom object, updating the sharingModel field for an object, and adding a new owner-based sharing rule isn’t supported.

2. Simultaneously updating the sharingModel field for an object and adding a new owner-based sharing rule isn’t supported.

3. Using API version 29.0, you can’t change the sharingModel of an object using Metadata API. Manually change the target org through the user interface.

4. Starting with API version 30.0, you can change the sharingModel of an object for internal users using Metadata API and the user interface.

5. Simultaneously updating the sharingModel field for an object and adding a new owner-based sharing rule isn’t supported in Metadata API. You can add an owner-based sharing rule when the org-wide default is public, and then update the sharingModel, which would result in a single sharing recalculation. You can deploy a criteria-based or guest user sharing rule and changes to the sharingModel field together using the Metadata API.

Please check the following article for reference.
https://help.salesforce.com/s/articleView?id=sf.deploy_special_behavior.htm&type=5