Switch Docker CI from gitlab to github

Adds buildx signing and helm chart publication.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

charts/smarter-device-manager/Chart.yaml

@@ -2,7 +2,7 @@ apiVersion: v2
 name: smarter-device-manager
 description: smarter-device-manager chart for SMARTER edge devices
 home: https://github.com/smarter-device-manager
-version: 0.0.5
+version: 0.0.6
 appVersion: v1.20.11
 kubeVersion: ">=1.16.0-0"
 keywords:

charts/smarter-device-manager/values.yaml

@@ -4,7 +4,7 @@ application:
   appName: smarter-device-manager
 
 image:
-  repository: registry.gitlab.com/smarter-project/smarter-device-manager
+  repository: ghcr.io/smarter-project/smarter-device-manager:v1.20.11
   # @default -- chart.appVersion
   tag: ""
   pullPolicy: IfNotPresent