Deployment fails with CloudFormation operation conflict error

[mcalligator]

Describe the bug
Deployment of the template fails with the following CloudFormation error:
A conflicting conditional operation is currently in progress against this resource. Please try again.

To Reproduce
Steps to reproduce the behavior:

1. Follow the instructions in the README.md to build and deploy the template.
2. Wait for the failure notification.
3. Check under Events in the CloudFormation Stack created for the detected root cause.
4. Confirm that this matches the error message reported above and pertains to the WebsiteS3Bucket resource.

Expected behavior
The deployment should complete successfully with no errors (provided that the values supplied for its config are valid).

Screenshots
N/A

Desktop (please complete the following information):
Not that this is relevant, but here goes:

• OS: Windows 11 with WSL running Arch
• Browser: Chrome
• Version: 130.0.6723.70 (Official Build) (64-bit)

Smartphone (please complete the following information):
N/A

Additional context
Not that this is likely to be relevant, but the contracts deployment option is utilised.
I have diagnosed the issue, and established that it occurs because the WebsiteS3Bucket resource has an unconditional reference to WebsiteS3BucketName, whereas the WebsiteS3Bucket output is conditional. This seems to cause a race condition with CloudFormation, which then results in the operation failing. I have a fix ready, for which I'll submit a PR.