Cleanup after v3.19.0
### Improvements
-- [codegen/go] - Remove `ResourcePtr` types from generated SDKs. Besides being
- unnecessary--`Resource` types already accommodate `nil` to indicate the lack of
- a value--the implementation of `Ptr` types for resources was incorrect, making
- these types virtually unusable in practice.
- [#8449](https://github.com/pulumi/pulumi/pull/8449)
-
-- Allow interpolating plugin custom server URLs.
- [#8507](https://github.com/pulumi/pulumi/pull/8507)
### Bug Fixes
-- [cli/engine] - Accurately computes the fields changed when diffing with unhelpful providers. This
- allows the `replaceOnChanges` feature to be respected for all providers.
- [#8488](https://github.com/pulumi/pulumi/pull/8488)
-
-- [codegen/go] - Respect default values in Pulumi object types.
- [#8411](https://github.com/pulumi/pulumi/pull/8400)
