Set correct permissions for linux

[resterle]

As described under "Linux->Manual" here: https://developer.1password.com/docs/cli/get-started/

[NeoHsu]

Thanks for the contribution, and sorry for the long delay in handling this.

The Linux app integration permissions issue has now been addressed on master in a slightly different way. The installer now applies the onepassword-cli group and setgid bit on a best-effort basis when the group exists and the current user has permission, so asdf install will not fail for users who cannot run chgrp. The README also documents the manual sudo chgrp / sudo chmod g+s steps for users who need to enable 1Password app integration.

Because this PR's core change is now covered, and the current implementation avoids failing installs when permissions are unavailable, I'm going to close this PR without merging. Thanks again for pointing this out.