fixup! fixup! Use Signed Binaries for Docker Build

Author: sheylatrudo

.pipelines/build/scripts/azure-ipam.sh

@@ -9,7 +9,7 @@ mkdir -p "$OUT_DIR"/bin
 mkdir -p "$OUT_DIR"/files
 
 pushd "$REPO_ROOT"/azure-ipam
-  go build -v -a -trimpath \
+  GOOS="$OS" go build -v -a -trimpath \
     -o "$OUT_DIR"/bin/azure-ipam"$FILE_EXT" \
     -ldflags "-X github.com/Azure/azure-container-networking/azure-ipam/internal/buildinfo.Version="$AZURE_IPAM_VERSION" -X main.version="$AZURE_IPAM_VERSION"" \
     -gcflags="-dwarflocationlists=true" \