Publish multi-arch images with goreleaser

[PrasadG193]

ISSUE TYPE

• Feature Pull Request

SUMMARY

• Switch to goreleaser for building and publishing release
• Set BotKube version with build args
• Use docker manifest to build multi-arch image
• Update CI pipeline to build and push image using goreleaser

Fixes #504

$ docker manifest inspect ghcr.io/prasadg193/botkube:latest
{
   "schemaVersion": 2,
   "mediaType": "application/vnd.docker.distribution.manifest.list.v2+json",
   "manifests": [
      {
         "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
         "size": 1370,
         "digest": "sha256:64d94709256eb85452afa06aa15574724266fa6b82b70654ff6b03c467d5a5e4",
         "platform": {
            "architecture": "amd64",
            "os": "linux"
         }
      },
      {
         "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
         "size": 1160,
         "digest": "sha256:525d79e629637fd1ae3530223fa380aea26ed299a1fd9ae2787721f4cc33dad5",
         "platform": {
            "architecture": "amd64",
            "os": "linux"
         }
      },
      {
         "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
         "size": 1160,
         "digest": "sha256:ef72bc09078929c8aed1161f86c2c86523f6fac664094a034c737ffd582f3ea7",
         "platform": {
            "architecture": "arm64",
            "os": "linux"
         }
      },
      {
         "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
         "size": 1160,
         "digest": "sha256:990cd2c6b522a3a69ba73ee83ed0ae306102369f02d09891de8fbfd024d37e87",
         "platform": {
            "architecture": "arm",
            "os": "linux",
            "variant": "v7"
         }
      }
   ]
}

[PrasadG193]

@xunholy PTAL

[PrasadG193]

Ref: Building multi-arch images with goreleaser: https://carlosbecker.com/posts/multi-platform-docker-images-goreleaser-gh-actions/