refactor(socketforward): migrate from x/net/context to std context

AGENTS.md

@@ -0,0 +1,7 @@
+# Repository Information
+
+This repository is a fork of [moby/buildkit](https://github.com/moby/buildkit). Its primary use is by [earthbuild/earthbuild](https://github.com/earthbuild/earthbuild).
+
+## Guidelines
+
+- Any code changes must be kept to a minimum to reduce the potential for merge conflicts with upstream `moby/buildkit`.

session/socketforward/copy.go

@@ -1,10 +1,10 @@
 package socketforward
 
 import (
+	"context"
 	"io"
 
 	"github.com/pkg/errors"
-	context "golang.org/x/net/context"
 	"golang.org/x/sync/errgroup"
 )
 

session/socketforward/socket.go

@@ -1,13 +1,13 @@
 package socketforward
 
 import (
+	"context"
 	"net"
 	"os"
 	"path/filepath"
 
 	"github.com/moby/buildkit/session"
 	"github.com/pkg/errors"
-	context "golang.org/x/net/context"
 	"golang.org/x/sync/errgroup"
 	"google.golang.org/grpc/metadata"
 )