Pass --parallelism 1 to serialize the stack deployments. The error comes from concurrent processes racing on the same provider binary files, so removing the concurrency removes the race. If you need parallel speed back, split the stacks into separate deploy invocations that do not share provider state, rather than fighting the file locking.

Context: GitHub issue hashicorp/terraform-cdk#2741 (closed): deploying multiple stacks in parallel intermittently fails with text file busy errors when the stacks share the same provider. Maintainer ansgarm gives the workaround directly in the thread.