Remove deprecated platforms package

Signed-off-by: Derek McGowan <derek@mcg.dev>

plugins/snapshots/blockfile/plugin/plugin.go

@@ -19,9 +19,9 @@ package plugin
 import (
 	"errors"
 
-	"github.com/containerd/containerd/v2/platforms"
 	"github.com/containerd/containerd/v2/plugins"
 	"github.com/containerd/containerd/v2/plugins/snapshots/blockfile"
+	"github.com/containerd/platforms"
 	"github.com/containerd/plugin"
 	"github.com/containerd/plugin/registry"
 )