Build package for GL-MT300N-V2 on OpenWRT

I’m trying to build tailscale for Mango router (running OpenWRT) using this guide. When I try to do opkg install /tmp/tailscaled_1.32.3-1_mipsel_24kc.ipk I get pkg_hash_fetch_best_installation_candidate: Packages for tailscaled found, but incompatible with the architectures configured. I’m not sure what is wrong, I changed the build command to env GOOS=linux GOARCH=mipsle GOMIPS=softfloat go build -o tailscale.combined -tags ts_include_cli -trimpath -ldflags="-s -w" ./cmd/tailscaled hoping that would the right arch for the target ramips. Can someone please unblock me on this?

I did a bit of Google search and I was told the right arch for ramips is mips32le. I tried to build on this image, but it failed as the Golang version is probably too old.