Update some build tags since go1.22+ is now required

internal/crypto/ptls/old.go

@@ -1,14 +0,0 @@
-// Copyright 2021-2023 the Pinniped contributors. All Rights Reserved.
-// SPDX-License-Identifier: Apache-2.0
-
-//go:build !go1.19
-
-package ptls
-
-func init() {
-	// cause compile time failure if an older version of Go is used
-	`Pinniped's TLS configuration makes assumptions about how the Go standard library implementation of TLS works.
-It particular, we rely on the server controlling cipher suite selection.  For these assumptions to hold, Pinniped
-must be compiled with Go 1.19+.  If you are seeing this error message, your attempt to compile Pinniped with an
-older Go compiler was explicitly failed to prevent an unsafe configuration.`
-}