[liburing] Adds liburing package (#35762)

* [liburing] Adds liburing package
* Update var/spack/repos/builtin/packages/liburing/package.py
* [liburing] Added conflicts for darwin and windows platforms

---------

Co-authored-by: Tamara Dahlgren <35777542+tldahlgren@users.noreply.github.com>

var/spack/repos/builtin/packages/liburing/package.py

@@ -0,0 +1,24 @@
+# Copyright 2013-2023 Lawrence Livermore National Security, LLC and other
+# Spack Project Developers. See the top-level COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+
+from spack.package import *
+
+
+class Liburing(AutotoolsPackage):
+    """This is the io_uring library, liburing. liburing provides helpers
+    to setup and teardown io_uring instances, and also a simplified interface
+    for applications that don't need (or want) to deal with the full kernel
+    side implementation."""
+
+    homepage = "https://github.com/axboe/liburing"
+    url = "https://github.com/axboe/liburing/archive/refs/tags/liburing-2.3.tar.gz"
+    git = "https://github.com/axboe/liburing.git"
+
+    version("master", branch="master")
+    version("2.3", sha256="60b367dbdc6f2b0418a6e0cd203ee0049d9d629a36706fcf91dfb9428bae23c8")
+
+    conflicts("platform=darwin", msg="Only supported on 'linux' and 'cray'")
+    conflicts("platform=windows", msg="Only supported on 'linux' and 'cray'")