Revert "Use busybox for runner base (#1934)"

This reverts commit 8d3db33.

Dockerfile

@@ -1,20 +1,19 @@
 # syntax=docker/dockerfile:1
 
 # Base image and static SDK have to be updated together.
-FROM --platform=$BUILDPLATFORM swift:6.0.2 AS builder
+FROM --platform=$BUILDPLATFORM swift:6.0.1 AS builder
 WORKDIR /workspace
 RUN swift sdk install \
-	https://download.swift.org/swift-6.0.2-release/static-sdk/swift-6.0.2-RELEASE/swift-6.0.2-RELEASE_static-linux-0.0.1.artifactbundle.tar.gz \
-	--checksum aa5515476a403797223fc2aad4ca0c3bf83995d5427fb297cab1d93c68cee075
+	https://download.swift.org/swift-6.0.1-release/static-sdk/swift-6.0.1-RELEASE/swift-6.0.1-RELEASE_static-linux-0.0.1.artifactbundle.tar.gz \
+	--checksum d4f46ba40e11e697387468e18987ee622908bc350310d8af54eb5e17c2ff5481
 
 COPY . /workspace
 ARG TARGETPLATFORM
 RUN --mount=type=cache,target=/workspace/.build,id=build-$TARGETPLATFORM \
 	./Scripts/build-linux-release.sh && \
 	cp /workspace/.build/release/swiftformat /workspace
 
-# https://github.com/nicklockwood/SwiftFormat/issues/1930
-FROM busybox:stable AS runner
+FROM scratch AS runner
 COPY --from=builder /workspace/swiftformat /usr/bin/swiftformat
 ENTRYPOINT [ "/usr/bin/swiftformat" ]
 CMD ["."]