limit threads and jobs to 1 to avoid OOM (exit 9)

Author: srijan-deepsource

Dockerfile

@@ -1,4 +1,4 @@
 FROM swift:6.1.1-jammy as swift-format-builder
 ADD . /toolbox
 WORKDIR /toolbox
-RUN swift build -c release --static-swift-stdlib
+RUN swift build -v -j 1 -c release --static-swift-stdlib -Xswiftc -num-threads -Xswiftc 1