add metadata file to ci artifacts (#91)

Author: mise42

.github/workflows/build.yml

@@ -156,7 +156,11 @@ jobs:
         uses: actions/upload-artifact@v4
         with:
           name: guest-${{ matrix.guest }}
-          path: output/guest-${{ matrix.guest }}.polkavm
+          path: |
+            output/guest-${{ matrix.guest }}.polkavm
+            output/guest-${{ matrix.guest }}-metadata.bin
+            output/guest-${{ matrix.guest }}-metadata.json
+          if-no-files-found: warn
           retention-days: 1
 
   # Collect all guest artifacts (optional - for when you need all guests together)