Revert "Remove vendored plugin server" (#2438)

Reverts #2410

---------

Co-authored-by: guineveresaenger <[email protected]>

pf/internal/plugin/package.go

@@ -0,0 +1,24 @@
+// Copyright 2016-2023, Pulumi Corporation.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// The code in this package implements Context-preserving provider server and is forked from pulumi/pulumi.
+//
+// We have started to make edits to customize this for pf. This includes secret handling.
+//
+// When https://github.com/pulumi/pulumi/issues/12010 is complete this may need to be rewritten to the newly introduced
+// APIs.
+//
+// An attempt to upstream the Context preservation improvement in this code was rejected in
+// https://github.com/pulumi/pulumi/pull/12429.
+package plugin

pf/internal/plugin/provider_context.go

@@ -85,11 +85,9 @@ type ProviderWithContext interface {
 	GetMappingsWithContext(ctx context.Context, key string) ([]string, error)
 
 	ParameterizeWithContext(context.Context, plugin.ParameterizeRequest) (plugin.ParameterizeResponse, error)
-
-	Attach(address string) error
 }
 
-func NewProvider(p ProviderWithContext) plugin.GrpcProvider {
+func NewProvider(p ProviderWithContext) plugin.Provider {
 	return &provider{ProviderWithContext: p}
 }
 
@@ -100,10 +98,6 @@ type provider struct {
 
 var _ plugin.Provider = (*provider)(nil)
 
-func (prov *provider) Attach(address string) error {
-	return prov.ProviderWithContext.Attach(address)
-}
-
 func (prov *provider) Pkg() tokens.Package { return prov.ProviderWithContext.Pkg() }
 
 func (prov *provider) Parameterize(