ci: add dev branch support for Docker image builds

Author: vastsa

.github/workflows/docker-image.yml

@@ -5,6 +5,7 @@ on:
   push:
     branches:
       - master
+      - dev
     tags:
       - 'v*'
 
@@ -31,6 +32,7 @@ jobs:
             type=ref,event=pr
             type=semver,pattern={{version}}
             type=semver,pattern={{major}}.{{minor}}
+            type=raw,value=dev,enable=${{ github.ref == 'refs/heads/dev' }}
             type=raw,value=beta,enable={{is_default_branch}}
             type=raw,value=latest,enable={{is_default_branch}}