guix: Rename Windows unsigned binaries to unsigned.zip

As codesigned binaries will be published, the unsigned ones should be
clearly marked as such.

Author: achow101

contrib/guix/libexec/build.sh

@@ -337,8 +337,8 @@ mkdir -p "$DISTSRC"
                     | xargs -0r touch --no-dereference --date="@${SOURCE_DATE_EPOCH}"
                 find "${DISTNAME}" -not -name "*.dbg" \
                     | sort \
-                    | zip -X@ "${OUTDIR}/${DISTNAME}-${HOST//x86_64-w64-mingw32/win64}.zip" \
-                    || ( rm -f "${OUTDIR}/${DISTNAME}-${HOST//x86_64-w64-mingw32/win64}.zip" && exit 1 )
+                    | zip -X@ "${OUTDIR}/${DISTNAME}-${HOST//x86_64-w64-mingw32/win64}-unsigned.zip" \
+                    || ( rm -f "${OUTDIR}/${DISTNAME}-${HOST//x86_64-w64-mingw32/win64}-unsigned.zip" && exit 1 )
                 find "${DISTNAME}" -name "*.dbg" -print0 \
                     | xargs -0r touch --no-dereference --date="@${SOURCE_DATE_EPOCH}"
                 find "${DISTNAME}" -name "*.dbg" \