migrate woodpecker to external mysql

woodpecker/woodpecker-server.yml

@@ -79,6 +79,11 @@ spec:
                 secretKeyRef:
                   name: woodpecker-secret
                   key: WOODPECKER_AGENT_SECRET
+            - name: "WOODPECKER_DATABASE_DRIVER"
+              value: "mysql"
+          envFrom:
+            - secretRef:
+                name: woodpecker-mysql
           volumeMounts:
             - name: woodpecker-data
               mountPath: /var/lib/woodpecker