cmd/govulncheck: remove gotypesalias.go (not needed anymore)

Fixes #77335.
For #76472.

Change-Id: I3c76d6b90fa1c7b8fae892c75d0fc13c83dc2ad9
Reviewed-on: https://go-review.googlesource.com/c/vuln/+/739740
Auto-Submit: Robert Griesemer <gri@google.com>
Reviewed-by: Robert Griesemer <gri@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Damien Neil <dneil@google.com>

cmd/govulncheck/gotypesalias.go

diff --git a/cmd/govulncheck/gotypesalias.go b/cmd/govulncheck/gotypesalias.go
deleted file mode 100644
index 288c10c..0000000
--- a/cmd/govulncheck/gotypesalias.go
+++ /dev/null
@@ -1,12 +0,0 @@
-// Copyright 2024 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build go1.23
-
-//go:debug gotypesalias=1
-
-package main
-
-// Materialize aliases whenever the go toolchain version is after 1.23 (#69772).
-// Remove this file after go.mod >= 1.23 (which implies gotypesalias=1).