try the docker-bake method

.github/workflows/ci.yml

@@ -35,7 +35,3 @@ jobs:
       with:
         files: |
           ./docker-bake.hcl
-        set: |
-          *.secrets.type=file
-          *.secrets.id=composer_auth
-          *.secrets.src=composer-auth.json

docker-bake.hcl

@@ -25,6 +25,10 @@ target "app" {
     "${REGISTRY}:${tgt}-%s",
     compact(["latest", VERSION])
   ) : []
+
+  secret = [
+    "type=file,id=composer_auth,src=${HOME}/.composer/auth.json"
+  ]
 }
 
 target "app-httpd" {