.*: bump golang.org/x/tools to v0.16.1

Bumping tools to include the fix for a nil pointer
deref error in go/types. See golang/go#64812
for more details.

This fix is needed for when we bump to go1.22.

Signed-off-by: Madhav Jivrajani <madhav.jiv@gmail.com>

vendor/golang.org/x/tools/go/packages/external.go

@@ -12,8 +12,8 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
-	exec "golang.org/x/sys/execabs"
 	"os"
+	"os/exec"
 	"strings"
 )