all: use Go 1.21 slices, maps instead of x/exp/{slices,maps}

Updates #8419

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

ipn/ipnlocal/cert.go

@@ -27,12 +27,12 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
+	"slices"
 	"strings"
 	"sync"
 	"time"
 
 	"github.com/tailscale/golang-x-crypto/acme"
-	"golang.org/x/exp/slices"
 	"tailscale.com/atomicfile"
 	"tailscale.com/envknob"
 	"tailscale.com/hostinfo"

ipn/ipnlocal/cert_test.go

@@ -18,7 +18,6 @@ import (
 	"time"
 
 	"github.com/google/go-cmp/cmp"
-	"golang.org/x/exp/maps"
 	"tailscale.com/ipn/store/mem"
 )
 
@@ -112,7 +111,7 @@ func TestShouldStartDomainRenewal(t *testing.T) {
 	reset := func() {
 		renewMu.Lock()
 		defer renewMu.Unlock()
-		maps.Clear(renewCertAt)
+		clear(renewCertAt)
 	}
 
 	mustMakePair := func(template *x509.Certificate) *TLSCertKeyPair {

ipn/ipnlocal/local.go

@@ -20,6 +20,7 @@ import (
 	"os/user"
 	"path/filepath"
 	"runtime"
+	"slices"
 	"sort"
 	"strconv"
 	"strings"
@@ -29,7 +30,6 @@ import (
 
 	"go4.org/mem"
 	"go4.org/netipx"
-	"golang.org/x/exp/slices"
 	"gvisor.dev/gvisor/pkg/tcpip"
 	"tailscale.com/client/tailscale/apitype"
 	"tailscale.com/control/controlclient"

ipn/ipnlocal/peerapi.go

@@ -22,6 +22,7 @@ import (
 	"path"
 	"path/filepath"
 	"runtime"
+	"slices"
 	"sort"
 	"strconv"
 	"strings"
@@ -32,7 +33,6 @@ import (
 	"unicode/utf8"
 
 	"github.com/kortschak/wol"
-	"golang.org/x/exp/slices"
 	"golang.org/x/net/dns/dnsmessage"
 	"golang.org/x/net/http/httpguts"
 	"tailscale.com/client/tailscale/apitype"

ipn/ipnlocal/profiles.go

@@ -10,10 +10,10 @@ import (
 	"math/rand"
 	"net/netip"
 	"runtime"
+	"slices"
 	"strings"
 	"time"
 
-	"golang.org/x/exp/slices"
 	"tailscale.com/envknob"
 	"tailscale.com/ipn"
 	"tailscale.com/types/logger"

ipn/ipnlocal/serve.go

@@ -17,12 +17,12 @@ import (
 	"net/url"
 	"os"
 	"path"
+	"slices"
 	"strconv"
 	"strings"
 	"sync"
 	"time"
 
-	"golang.org/x/exp/slices"
 	"tailscale.com/ipn"
 	"tailscale.com/logtail/backoff"
 	"tailscale.com/net/netutil"

ipn/ipnlocal/ssh.go

@@ -20,12 +20,12 @@ import (
 	"os/exec"
 	"path/filepath"
 	"runtime"
+	"slices"
 	"strings"
 	"sync"
 
 	"github.com/tailscale/golang-x-crypto/ssh"
 	"go4.org/mem"
-	"golang.org/x/exp/slices"
 	"tailscale.com/tailcfg"
 	"tailscale.com/util/lineread"
 	"tailscale.com/util/mak"