remove deprecated pkg/symlink

This package was deprecated in dc3c382b343e45c9c84e0ac01a13e09c12e88bc7, which
was part of the 20.10 release, so consumers of this package should've been
able to migrate to the new location.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

pkg/symlink/deprecated.go

@@ -1,12 +0,0 @@
-package symlink // import "github.com/docker/docker/pkg/symlink"
-
-import "github.com/moby/sys/symlink"
-
-var (
-	// EvalSymlinks is deprecated and moved to github.com/moby/sys/symlink
-	// Deprecated: use github.com/moby/sys/symlink.EvalSymlinks instead
-	EvalSymlinks = symlink.EvalSymlinks
-	// FollowSymlinkInScope is deprecated and moved to github.com/moby/sys/symlink
-	// Deprecated: use github.com/moby/sys/symlink.FollowSymlinkInScope instead
-	FollowSymlinkInScope = symlink.FollowSymlinkInScope
-)