feature/taildrop, ipn/ipnlocal: remove leftover dup calls to osshare

I'd moved the osshare calls to feature/taildrop hooks, but forgot to
remove them from ipnlocal, or lost them during a rebase.

But then I noticed cmd/tailscaled also had some, so turn those into a
hook.

Updates #12614

Change-Id: I024fb1d27fbcc49c013158882ee5982c2737037d
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

cmd/k8s-operator/depaware.txt

@@ -936,7 +936,6 @@ tailscale.com/cmd/k8s-operator dependencies: (generated by github.com/tailscale/
         tailscale.com/util/nocasemaps                                from tailscale.com/types/ipproto
      💣 tailscale.com/util/osdiag                                    from tailscale.com/ipn/localapi
    W 💣 tailscale.com/util/osdiag/internal/wsc                       from tailscale.com/util/osdiag
-        tailscale.com/util/osshare                                   from tailscale.com/ipn/ipnlocal
         tailscale.com/util/osuser                                    from tailscale.com/ipn/ipnlocal
         tailscale.com/util/race                                      from tailscale.com/net/dns/resolver
         tailscale.com/util/racebuild                                 from tailscale.com/logpolicy

cmd/tailscaled/depaware.txt

@@ -253,6 +253,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
         tailscale.com/clientupdate                                   from tailscale.com/client/web+
   LW    tailscale.com/clientupdate/distsign                          from tailscale.com/clientupdate
         tailscale.com/cmd/tailscaled/childproc                       from tailscale.com/cmd/tailscaled+
+        tailscale.com/cmd/tailscaled/tailscaledhooks                 from tailscale.com/cmd/tailscaled+
         tailscale.com/control/controlbase                            from tailscale.com/control/controlhttp+
         tailscale.com/control/controlclient                          from tailscale.com/cmd/tailscaled+
         tailscale.com/control/controlhttp                            from tailscale.com/control/controlclient

cmd/tailscaled/install_windows.go

@@ -15,9 +15,9 @@ import (
 	"golang.org/x/sys/windows"
 	"golang.org/x/sys/windows/svc"
 	"golang.org/x/sys/windows/svc/mgr"
+	"tailscale.com/cmd/tailscaled/tailscaledhooks"
 	"tailscale.com/logtail/backoff"
 	"tailscale.com/types/logger"
-	"tailscale.com/util/osshare"
 )
 
 func init() {
@@ -81,8 +81,9 @@ func installSystemDaemonWindows(args []string) (err error) {
 }
 
 func uninstallSystemDaemonWindows(args []string) (ret error) {
-	// Remove file sharing from Windows shell (noop in non-windows)
-	osshare.SetFileSharingEnabled(false, logger.Discard)
+	for _, f := range tailscaledhooks.UninstallSystemDaemonWindows {
+		f()
+	}
 
 	m, err := mgr.Connect()
 	if err != nil {

cmd/tailscaled/tailscaledhooks/tailscaledhooks.go

@@ -0,0 +1,12 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+// Package tailscaledhooks provides hooks for optional features
+// to add to during init that tailscaled calls at runtime.
+package tailscaledhooks
+
+import "tailscale.com/feature"
+
+// UninstallSystemDaemonWindows is called when the Windows
+// system daemon is uninstalled.
+var UninstallSystemDaemonWindows feature.Hooks[func()]