CI: Generate a separate artifact for FDB

.github/workflows/build.yml

@@ -130,11 +130,11 @@ jobs:
           mkdir -p "${root}/target/${target}/release" && cd "$_"
 
           if [ "${USE_FOUNDATIONDB:-0}" = 1 ]; then
-            build -p mail-server --features foundationdb
-          else
-            build -p mail-server
+            build -p mail-server --no-default-features --features "foundationdb elastic s3 redis"
+            artifact stalwart-mail stalwart-mail-foundationdb
           fi
-          build -p stalwart-cli
+
+          build -p mail-server -p stalwart-cli
 
           artifact stalwart-mail
           artifact stalwart-cli