use highest zstd compression level

Level 20 is recommended

Requires less 1GiB of memory for compression
Requires about 32MiB of memory for decompression
Some package save space more then 50%

But will use more time on pre-compressed packages without gain, for example game data.

$ zstd -20vv --ultra bigfile

*** zstd command line interface 64-bits v1.5.2, by Yann Collet ***
--zstd=wlog=25,clog=25,hlog=23,slog=7,mml=3,tlen=256,strat=9
--format=.zst --block-size=0 --memory=134217728 --threads=1 --content-size
Decompression will require 33554432 B of memory

``` -rw-r--r-- 1 runner docker 177M Sep 19 06:59 nerd-fonts-otf-2.2.2_1.x86_64.xbps -rw-r--r-- 1 runner docker 60M Sep 22 11:39 nerd-fonts-otf.tar.zst -rw-r--r-- 1 runner docker 188M Jun 30 00:21 qemu-7.0.0_1.x86_64.xbps -rw-r--r-- 1 runner docker 75M Sep 22 11:41 qemu.tar.zst -rw-r--r-- 1 runner docker 59M Feb 19 2021 gcc-10.2.1pre1_3.x86_64.xbps -rw-r--r-- 1 runner docker 25M Sep 22 11:41 gcc.tar.zst -rw-r--r-- 1 runner docker 13M Mar 21 2022 dolphin-emu-5.0.16101_1.x86_64.xbps -rw-r--r-- 1 runner docker 6.9M Sep 22 11:41 dolphin-emu.tar.zst -rw-r--r-- 1 runner docker 5.5M Feb 12 2021 binutils-2.35.1_4.x86_64.xbps -rw-r--r-- 1 runner docker 3.0M Sep 22 11:41 binutils.tar.zst -rw-r--r-- 1 runner docker 418M Sep 19 07:03 nerd-fonts-ttf-2.2.2_1.x86_64.xbps -rw-r--r-- 1 runner docker 242M Sep 22 11:43 nerd-fonts-ttf.tar.zst -rw-r--r-- 1 runner docker 92M Sep 14 07:07 font-iosevka-16.2.0_1.x86_64.xbps -rw-r--r-- 1 runner docker 58M Sep 22 11:44 font-iosevka.tar.zst -rw-r--r-- 1 runner docker 11M Apr 19 21:17 keepassxc-2.7.1_1.x86_64.xbps -rw-r--r-- 1 runner docker 7.6M Sep 22 11:44 keepassxc.tar.zst -rw-r--r-- 1 runner docker 7.2M Aug 31 16:36 git-2.37.3_1.x86_64.xbps -rw-r--r-- 1 runner docker 5.2M Sep 22 11:44 git.tar.zst -rw-r--r-- 1 runner docker 19M Sep 16 21:33 vscode-1.71.2_1.x86_64.xbps -rw-r--r-- 1 runner docker 14M Sep 22 11:45 vscode.tar.zst -rw-r--r-- 1 runner docker 14M Mar 18 2022 perl-5.34.1_1.x86_64.xbps -rw-r--r-- 1 runner docker 11M Sep 22 11:45 perl.tar.zst -rw-r--r-- 1 runner docker 121M Sep 16 21:49 libwine-7.17_1.x86_64.xbps -rw-r--r-- 1 runner docker 97M Sep 22 11:46 libwine.tar.zst -rw-r--r-- 1 runner docker 7.4M Jul 4 2021 grub-2.06_2.x86_64.xbps -rw-r--r-- 1 runner docker 6.0M Sep 22 11:46 grub.tar.zst -rw-r--r-- 1 runner docker 45M Sep 8 06:10 clang-12.0.1_3.x86_64.xbps -rw-r--r-- 1 runner docker 37M Sep 22 11:46 clang.tar.zst -rw-r--r-- 1 runner docker 3.3M Oct 21 2020 dejavu-fonts-ttf-2.37_2.x86_64.xbps -rw-r--r-- 1 runner docker 2.6M Sep 22 11:46 dejavu-fonts-ttf.tar.zst -rw-r--r-- 1 runner docker 8.4M Jun 1 21:31 gtk+3-3.24.34_1.x86_64.xbps -rw-r--r-- 1 runner docker 6.9M Sep 22 11:46 gtk+3.tar.zst -rw-r--r-- 1 runner docker 140M Aug 24 17:44 rust-std-1.63.0_1.x86_64.xbps -rw-r--r-- 1 runner docker 114M Sep 22 11:47 rust-std.tar.zst -rw-r--r-- 1 runner docker 44M Aug 29 00:31 virtualbox-ose-6.1.36_1.x86_64.xbps -rw-r--r-- 1 runner docker 36M Sep 22 11:47 virtualbox-ose.tar.zst -rw-r--r-- 1 runner docker 96M Sep 4 12:00 chromium-105.0.5195.102_1.x86_64.xbps -rw-r--r-- 1 runner docker 81M Sep 22 11:47 chromium.tar.zst -rw-r--r-- 1 runner docker 769M Aug 21 04:00 google-fonts-ttf-20220819_1.x86_64.xbps -rw-r--r-- 1 runner docker 651M Sep 22 11:50 google-fonts-ttf.tar.zst -rw-r--r-- 1 runner docker 44M Sep 1 07:05 blender-3.0.0_5.x86_64.xbps -rw-r--r-- 1 runner docker 37M Sep 22 11:50 blender.tar.zst nerd-fonts-otf: save 66.17% qemu: save 60.58% gcc: save 56.99% dolphin-emu: save 46.31% binutils: save 46.07% nerd-fonts-ttf: save 42.11% font-iosevka: save 37.96% keepassxc: save 31.67% git: save 28.52% vscode: save 26.32% perl: save 22.63% libwine: save 19.62% grub: save 19.22% clang: save 19.04% dejavu-fonts-ttf: save 18.78% gtk+3: save 18.67% rust-std: save 18.17% virtualbox-ose: save 17.57% chromium: save 15.58% google-fonts-ttf: save 15.33% blender: save 15.30% ```

void-linux / xbps

use highest zstd compression level #508