When attaching a container to a network, the provided MacAddress is always ignored

Description

When using the /v1.44/networks/{id}/connect endpoint (https://docs.docker.com/engine/api/v1.44/#tag/Network/operation/NetworkConnect) to connect a container to a network, the MacAddress field seems to be always ignored. When instead providing the same network configuration on creating a container, the MacAddress field is used.

Reproduce

1. Use https://docs.docker.com/engine/api/v1.44/#tag/Container/operation/ContainerCreate to create a container
2. Use https://docs.docker.com/engine/api/v1.44/#tag/Network/operation/NetworkConnect to attach the container to a network, providing a MacAddress (in the simplest case, without any other config)

This unfortunately cannot be done with the CLI tool since docker network connect does not allow to specify the MAC address. (Which might explain why this wasn't noticed before.)

Expected behavior

Container uses the specified MAC address in the container.

docker version

Client:
 Version:           27.0.3
 API version:       1.46
 Go version:        go1.22.4
 Git commit:        7d4bcd863a
 Built:             Mon Jul  1 21:15:54 2024
 OS/Arch:           linux/amd64
 Context:           default

Server:
 Engine:
  Version:          27.0.3
  API version:      1.46 (minimum version 1.24)
  Go version:       go1.22.4
  Git commit:       662f78c0b1
  Built:            Mon Jul  1 21:15:54 2024
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          v1.7.19
  GitCommit:        2bf793ef6dc9a18e00cb12efb64355c2c9d5eb41.m
 runc:
  Version:          1.1.13
  GitCommit:        
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

(also happens with other versions)

docker info

Client:
 Version:    27.0.3
 Context:    default
 Debug Mode: false
 Plugins:
  buildx: Docker Buildx (Docker Inc.)
    Version:  0.15.1
    Path:     /usr/lib/docker/cli-plugins/docker-buildx
  compose: Docker Compose (Docker Inc.)
    Version:  2.29.0
    Path:     /usr/lib/docker/cli-plugins/docker-compose

Server:
 Containers: 3
  Running: 1
  Paused: 0
  Stopped: 2
 Images: 13
 Server Version: 27.0.3
 Storage Driver: overlay2
  Backing Filesystem: extfs
  Supports d_type: true
  Using metacopy: true
  Native Overlay Diff: false
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: systemd
 Cgroup Version: 2
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local splunk syslog
 Swarm: inactive
 Runtimes: runc io.containerd.runc.v2
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 2bf793ef6dc9a18e00cb12efb64355c2c9d5eb41.m
 runc version: 
 init version: de40ad0
 Security Options:
  seccomp
   Profile: builtin
  cgroupns
 Kernel Version: 6.9.9-arch1-1
 Operating System: Arch Linux
 OSType: linux
 Architecture: x86_64
 CPUs: 4
 Total Memory: 15.52GiB
 Name: xxx
 ID: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false

Additional Info

No response

Start by tracing the /v1.44/networks/{id}/connect endpoint and compare its handling of MacAddress with the ContainerCreate endpoint. Reproduce the report using the API, then verify that connecting a container with a supplied MacAddress results in that address being used.