avoid ./ prefix on tar paths

See https://github.com/ziglang/zig/issues/23152

.gitea/workflows/build.yaml

@@ -48,7 +48,7 @@ jobs:
           tar -czf ${{ runner.temp }}/${{ github.sha }}-with-models.tar.gz \
             --format ustar \
             -C zig-out/package \
-            .
+            *
       # Something in this PR broke this transform. I don't mind removing it, but
       # the PR attempts to handle situations with or without a prefix, but it
       # doesn't. I have not yet determined what the problem is, though