Merge bitcoin/bitcoin#28757: guix: Zip needs to include all files and set time to SOURCE_DATE_EPOCH

f6f18eeaa8 guix: Zip needs to include all files with time as SOURCE_DATE_EPOCH (Andrew Chow)

Pull request description:

  The zip for codesigned MacOS distribution needs to have all files included and have their timestamps set to the same value (`SOURCE_DATE_EPOCH`).

  This uses the same pattern for zip as is done for the other zip files produced by guix.

ACKs for top commit:
  hebasto:
    ACK f6f18eeaa8.
  TheCharlatan:
    ACK f6f18eeaa8

Tree-SHA512: 569ff0d8bfe76b9b111a2454478523eeb514b44b691be8b57b61415db88356c683582550ea67ebd5fb392b4f486be170a925067b507979090535ca41cbc7351b

contrib/guix/libexec/codesign.sh

@@ -86,7 +86,11 @@ mkdir -p "$DISTSRC"
             signapple apply dist/Bitcoin-Qt.app codesignatures/osx/dist
 
             # Make a .zip from dist/
-            zip "${OUTDIR}/${DISTNAME}-${HOST}.zip" dist/*
+            cd dist/
+            find . -print0 \
+                | xargs -0r touch --no-dereference --date="@${SOURCE_DATE_EPOCH}"
+            find . | sort \
+                | zip -X@ "${OUTDIR}/${DISTNAME}-${HOST}.zip"
             ;;
         *)
             exit 1