Bump github.com/containers/buildah from 1.8.4 to 1.11.4

Bumps [github.com/containers/buildah](https://github.com/containers/buildah) from 1.8.4 to 1.11.4.
- [Release notes](https://github.com/containers/buildah/releases)
- [Changelog](https://github.com/containers/buildah/blob/master/CHANGELOG.md)
- [Commits](https://github.com/containers/buildah/compare/v1.8.4...v1.11.4)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>
Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

vendor/github.com/gorilla/mux/test_helpers.go

@@ -0,0 +1,19 @@
+// Copyright 2012 The Gorilla Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package mux
+
+import "net/http"
+
+// SetURLVars sets the URL variables for the given request, to be accessed via
+// mux.Vars for testing route behaviour. Arguments are not modified, a shallow
+// copy is returned.
+//
+// This API should only be used for testing purposes; it provides a way to
+// inject variables into the request context. Alternatively, URL variables
+// can be set by making a route that captures the required variables,
+// starting a server and sending the request to that server.
+func SetURLVars(r *http.Request, val map[string]string) *http.Request {
+	return setVars(r, val)
+}