fix(dhcp): can not renew an ip address

The dhcp server is systemd-networkd, and the dhcp
plugin can request an ip but can not renew it.
The systemd-networkd just ignore the renew request.

```
2024/09/14 21:46:00 no DHCP packet received within 10s
2024/09/14 21:46:00 retrying in 31.529038 seconds
2024/09/14 21:46:42 no DHCP packet received within 10s
2024/09/14 21:46:42 retrying in 63.150490 seconds
2024/09/14 21:47:45 98184616c91f15419f5cacd012697f85afaa2daeb5d3233e28b0ec21589fb45a/iot/eth1: no more tries
2024/09/14 21:47:45 98184616c91f15419f5cacd012697f85afaa2daeb5d3233e28b0ec21589fb45a/iot/eth1: renewal time expired, rebinding
2024/09/14 21:47:45 Link "eth1" down. Attempting to set up
2024/09/14 21:47:45 98184616c91f15419f5cacd012697f85afaa2daeb5d3233e28b0ec21589fb45a/iot/eth1: lease rebound, expiration is 2024-09-14 22:47:45.309270751 +0800 CST m=+11730.048516519
```

Follow the https://datatracker.ietf.org/doc/html/rfc2131#section-4.3.6,
following options must not be sent in renew

- Requested IP Address
- Server Identifier

Since the upstream code has been inactive for 6 years,
we should switch to another dhcpv4 library.
The new selected one is https://github.com/insomniacslk/dhcp.

Signed-off-by: Songmin Li <lisongmin@protonmail.com>

vendor/github.com/insomniacslk/dhcp/dhcpv4/option_ips.go

@@ -0,0 +1,103 @@
+package dhcpv4
+
+import (
+	"fmt"
+	"net"
+	"strings"
+
+	"github.com/u-root/uio/uio"
+)
+
+// IPs are IPv4 addresses from a DHCP packet as used and specified by options
+// in RFC 2132, Sections 3.5 through 3.13, 8.2, 8.3, 8.5, 8.6, 8.9, and 8.10.
+//
+// IPs implements the OptionValue type.
+type IPs []net.IP
+
+// FromBytes parses an IPv4 address from a DHCP packet as used and specified by
+// options in RFC 2132, Sections 3.5 through 3.13, 8.2, 8.3, 8.5, 8.6, 8.9, and
+// 8.10.
+func (i *IPs) FromBytes(data []byte) error {
+	buf := uio.NewBigEndianBuffer(data)
+	if buf.Len() == 0 {
+		return fmt.Errorf("IP DHCP options must always list at least one IP")
+	}
+
+	*i = make(IPs, 0, buf.Len()/net.IPv4len)
+	for buf.Has(net.IPv4len) {
+		*i = append(*i, net.IP(buf.CopyN(net.IPv4len)))
+	}
+	return buf.FinError()
+}
+
+// ToBytes marshals IPv4 addresses to a DHCP packet as specified by RFC 2132,
+// Section 3.5 et al.
+func (i IPs) ToBytes() []byte {
+	buf := uio.NewBigEndianBuffer(nil)
+	for _, ip := range i {
+		buf.WriteBytes(ip.To4())
+	}
+	return buf.Data()
+}
+
+// String returns a human-readable representation of a list of IPs.
+func (i IPs) String() string {
+	s := make([]string, 0, len(i))
+	for _, ip := range i {
+		s = append(s, ip.String())
+	}
+	return strings.Join(s, ", ")
+}
+
+// GetIPs parses a list of IPs from code in o.
+func GetIPs(code OptionCode, o Options) []net.IP {
+	v := o.Get(code)
+	if v == nil {
+		return nil
+	}
+	var ips IPs
+	if err := ips.FromBytes(v); err != nil {
+		return nil
+	}
+	return []net.IP(ips)
+}
+
+// OptRouter returns a new DHCPv4 Router option.
+//
+// The Router option is described by RFC 2132, Section 3.5.
+func OptRouter(routers ...net.IP) Option {
+	return Option{
+		Code:  OptionRouter,
+		Value: IPs(routers),
+	}
+}
+
+// WithRouter updates a packet with the DHCPv4 Router option.
+func WithRouter(routers ...net.IP) Modifier {
+	return WithOption(OptRouter(routers...))
+}
+
+// OptNTPServers returns a new DHCPv4 NTP Server option.
+//
+// The NTP servers option is described by RFC 2132, Section 8.3.
+func OptNTPServers(ntpServers ...net.IP) Option {
+	return Option{
+		Code:  OptionNTPServers,
+		Value: IPs(ntpServers),
+	}
+}
+
+// OptDNS returns a new DHCPv4 Domain Name Server option.
+//
+// The DNS server option is described by RFC 2132, Section 3.8.
+func OptDNS(servers ...net.IP) Option {
+	return Option{
+		Code:  OptionDomainNameServer,
+		Value: IPs(servers),
+	}
+}
+
+// WithDNS modifies a packet with the DHCPv4 Domain Name Server option.
+func WithDNS(servers ...net.IP) Modifier {
+	return WithOption(OptDNS(servers...))
+}