fix: add required files to goreleaser docker build context

Author: larkinwc

.goreleaser.yml

@@ -76,6 +76,11 @@ dockers:
       - "ghcr.io/larkinwc/proxmox-lxc-compose:{{ .Version }}"
       - "ghcr.io/larkinwc/proxmox-lxc-compose:latest"
     dockerfile: Dockerfile
+    extra_files:
+      - go.mod
+      - go.sum
+      - cmd/
+      - pkg/
     build_flag_templates:
       - "--label=org.opencontainers.image.created={{.Date}}"
       - "--label=org.opencontainers.image.title={{.ProjectName}}"