Reducing noise in my OpenTofu/Terraform provider plans

Introduction Anyone who uses OpenTofu or Terraform extensively knows that “known after apply” entries can make a plan output frustratingly cluttered. These entries are normal during resource creation or after import, but they become distracting during unrelated updates. A little over a year ago, I began writing an OpenTofu/Terraform provider for Forgejo. It is the second provider I have written and I did not know all the tricks (I most certainly still do not!), but something clicked last month: I finally understood how to patch my code to make unmanaged attributes less noisy when updating. Example of the problem Most OpenTofu/Terraform providers want to enforce the configuration of the used resources as tightly as possible, and it often makes sense to do so. However, that model is less suitable for Forgejo, where users and other administrators also make changes through the webui. I always wanted my OpenTofu/Terraform provider to silently ignore whatever the admin chooses to manually…