ipn/store, feature/condregister: move AWS + Kube store registration to condregister

Otherwise they're uselessly imported by tsnet applications, even
though they do nothing. tsnet applications wanting to use these
already had to explicitly import them and use kubestore.New or
awsstore.New and assign those to their tsnet.Server.Store fields.

Updates #12614

Change-Id: I358e3923686ddf43a85e6923c3828ba2198991d4
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

ipn/store/store_aws.go

@@ -1,22 +0,0 @@
-// Copyright (c) Tailscale Inc & AUTHORS
-// SPDX-License-Identifier: BSD-3-Clause
-
-//go:build (ts_aws || (linux && (arm64 || amd64) && !android)) && !ts_omit_aws
-
-package store
-
-import (
-	"tailscale.com/ipn"
-	"tailscale.com/ipn/store/awsstore"
-	"tailscale.com/types/logger"
-)
-
-func init() {
-	Register("arn:", func(logf logger.Logf, arg string) (ipn.StateStore, error) {
-		ssmARN, opts, err := awsstore.ParseARNAndOpts(arg)
-		if err != nil {
-			return nil, err
-		}
-		return awsstore.New(logf, ssmARN, opts...)
-	})
-}

ipn/store/store_kube.go

@@ -1,21 +0,0 @@
-// Copyright (c) Tailscale Inc & AUTHORS
-// SPDX-License-Identifier: BSD-3-Clause
-
-//go:build (ts_kube || (linux && (arm64 || amd64) && !android)) && !ts_omit_kube
-
-package store
-
-import (
-	"strings"
-
-	"tailscale.com/ipn"
-	"tailscale.com/ipn/store/kubestore"
-	"tailscale.com/types/logger"
-)
-
-func init() {
-	Register("kube:", func(logf logger.Logf, path string) (ipn.StateStore, error) {
-		secretName := strings.TrimPrefix(path, "kube:")
-		return kubestore.New(logf, secretName)
-	})
-}