Is changing TTL to 1 for a device will prevent it from Hotspoting my Wifi

you probably can't.

I'm sure google knows this.

your hw isn't really relevant here ..

stolen from NFT-QoS unable to ratelimit using mac address - #2 by pavelgl.

nft add table bridge nft-qos-ttl
nft add chain bridge nft-qos-ttl download '{type filter hook postrouting priority 0; policy accept; }'
nft insert rule bridge nft-qos-ttl download ip ttl 63 limit rate over 1 mbytes/second drop

you'll have to experiment with the TTL value, and install the kmod-nft-bridge package.
there are probably prettier ways of solving it, but I'm not really familiar with nft.

this was tested on 24.10.0.