make generate fails on zfs with EAGAIN in pnpm

[Kerrnel]

make generate on a zfs filesystem fails with EAGAIN on copyfile due to pnpm issues

See hoppscotch/hoppscotch#4960

Workaround:

Adjust "pnpm install" in services/idp/Makefile to "pnpm install -f --prefer-offline --package-import-method=hardlink"