Add removal of duplicate lines to the build

[scolby33]

Use sort --unique to filter the downloaded blocklists before compressing them. This saves about 24MB uncompressed and 7MB compressed.

$ du -h bt_blocklists uniq bt_blocklists.gz uniq.gz
 54M    bt_blocklists
 30M    uniq
 15M    bt_blocklists.gz
8.1M    uniq.gz

https://github.com/scolby33/BT_BlockLists/runs/4661288837 example run, failed in the release step because I don't have access to this repo, but you can see in the update on master that it worked as expected.

[Naunter]

Aha! sort --unique! Why I not remember this one!

I was going to use awk + sed, it is a more complicated but not accurate and dump way....