dep: add libxml-2 for hwloc

Signed-off-by: vsoch <vsoch@users.noreply.github.com>

Author: vsoch

pixi.toml

@@ -46,6 +46,8 @@ libcxx = "*"
 libsodium = "*"
 argp-standalone = "*"
 libuuid = "*"
+libxml2 = "*"
+libxml2-devel = "*"
 
 [pypi-dependencies]
 setuptools = "*"