Changes to the Feedstock Output Validation Procedure

We have changed our feedstock output validation procedure. Instead of automatically adding new packages to existing feedstocks (e.g., when a new output is added), we will now require that maintainers submit a PR to add the new output via our admin-requests repository. New feedstocks created via staged-recipes will have their outputs added automatically. If you maintain a feedstock that regularly adds new outputs (e.g., llvmdev has libllvm18, libllvm19, etc.), you can use the admin-requsts repo to add a glob pattern that matches the pattern of your new outputs. We test these patterns aginst new outputs from the feedstock using the Python fnmatch module. Outputs from the feedstock that match a glob pattern will added automatically. Further details on package output validation can be found in our documentation.