Docker images don't work on ARM machines

**Describe the bug**
Following the instructions at https://gin.g-node.org/G-Node/Info/wiki/In+House, running the line `docker run -p 3000:3000 -p 2222:22 -d gnode/gin-web` results in the following error:

```
WARNING: The requested image's platform (linux/amd64) does not match the detected host platform (linux/arm64/v8) and no specific platform was requested
```

The container then immediately exits. I'm running on a Ubuntu VM using Canonical's Multipass (https://multipass.run/) on an M1 MacBook Pro. The M1 architecture is almost certainly the cause of this, since there doesn't appear to be any ARM builds on Docker Hub. This bug report is more of a request for those builds, if I'm honest.

**Gogs version and commit**
Docker image `latest`, which according to Docker Hub has SHA `105cad1f385ed5c5784dc4a55e5d2b2fd3ae09fb9a5b14d8c3dea693705182b5` at time of writing.

**Git version**
N/A

**Operating system**
Ubuntu 22.04.1 LTS, running on a VM via Multipass. Host system for VM is macOS 13.1.

```
$ uname -a
Linux gin1 5.15.0-56-generic #62-Ubuntu SMP Tue Nov 22 19:56:13 UTC 2022 aarch64 aarch64 aarch64 GNU/Linux
```

**Database**
N/A

**To Reproduce**
As above, running `docker run -p 3000:3000 -p 2222:22 -d gnode/gin-web` results in the following error:

```
WARNING: The requested image's platform (linux/amd64) does not match the detected host platform (linux/arm64/v8) and no specific platform was requested
```

**Can you reproduce the bug at https://try.gogs.io?**
No - bug occurs when attempting to run the docker image as instructed at https://gin.g-node.org/G-Node/Info/wiki/In+House, and try.gogs.io doesn't provide the facility to do this.

**Expected behavior**
A running GIN docker container.

**Actual behavior**
Error message as above, and no running instance of GIN in Docker.

**Screenshots**

**Additional context**