That is because you are installing a non-Artix version of Steam.
$ LC_ALL=C pacman -Si lib32/steam
Repository : lib32
Name : steam
Version : 1.0.0.74-1
Description : Valve's digital software delivery system
Architecture : x86_64
URL : https://steampowered.com/
Licenses : custom
Groups : None
Provides : None
Depends On : bash desktop-file-utils diffutils hicolor-icon-theme curl dbus freetype2 gdk-pixbuf2 ttf-font zenity lsb-release nss usbutils xorg-xrandr vulkan-driver
vulkan-icd-loader lsof python lib32-libgl lib32-gcc-libs lib32-libx11 lib32-libxss lib32-alsa-plugins lib32-libgpg-error lib32-nss lib32-vulkan-driver
lib32-vulkan-icd-loader
Optional Deps : steam-native-runtime: steam native runtime support
Conflicts With : None
Replaces : None
Download Size : 3.42 MiB
Installed Size : 3.60 MiB
Packager : Artix Build Bot <[email protected]>
Build Date : Sat Dec 11 00:02:31 2021
Validated By : MD5 Sum SHA-256 Sum Signature
$ LC_ALL=C pacman -Si world/webkit2gtk
Repository : world
Name : webkit2gtk
Version : 2.36.1-1
Description : Web content engine for GTK
Architecture : x86_64
URL : https://webkitgtk.org
Licenses : custom
Groups : None
Provides : libjavascriptcoregtk-4.0.so=18-64 libwebkit2gtk-4.0.so=37-64
Depends On : cairo fontconfig freetype2 libgcrypt glib2 gtk3 harfbuzz harfbuzz-icu icu libjpeg libsoup libxml2 zlib libpng sqlite atk libwebp at-spi2-core libegl
libgl libgles libwpe wpebackend-fdo libxslt libsecret libtasn1 enchant libx11 libxext libice libxt wayland libnotify hyphen openjpeg2 woff2 bubblewrap
libseccomp xdg-dbus-proxy gstreamer gst-plugins-base-libs libmanette libwpe-1.0.so=1-64 libWPEBackend-fdo-1.0.so=1-64
Optional Deps : geoclue: Geolocation support
gst-plugins-good: media decoding
gst-plugins-bad: media decoding
gst-libav: nonfree media decoding
Conflicts With : None
Replaces : None
Download Size : 24.69 MiB
Installed Size : 99.27 MiB
Packager : Artix Build Bot <[email protected]>
Build Date : Fri Apr 22 02:45:36 2022
Validated By : MD5 Sum SHA-256 Sum Signature
Read the wiki first in the future.