Make libbpf available on nixos

Author: patricoferris

packages/libbpf/libbpf.0.1.0/opam

@@ -37,9 +37,10 @@ dev-repo: "git+https://github.com/koonwen/ocaml-libbpf.git"
 # eBPF features by kernel version https://github.com/iovisor/bcc/blob/master/docs/kernel-versions.md
 # Fix to kernel >= 6.1 to provide bound BPF map types
 available: [ os = "linux" &
-	   (( os-distribution = "debian" & os-version >= "12" )    # Linux 6.1 & Libbpf 1.1.0
- 	   |( os-distribution = "ubuntu" & os-version >= "23.04" ) # Linux 6.2 & Libbpf 1.1.0
-	   |( os-distribution = "fedora" & os-version >= "38" ))   # Linux 6.2 & Libbpf 1.1.0
+	   (( os-distribution = "debian" & os-version >= "12" )     # Linux 6.1 & Libbpf 1.1.0
+ 	   |( os-distribution = "ubuntu" & os-version >= "23.04" )  # Linux 6.2 & Libbpf 1.1.0
+	   |( os-distribution = "fedora" & os-version >= "38" )     # Linux 6.2 & Libbpf 1.1.0
+           |( os-distribution = "nixos"  & os-version >= "23.05" )) # Linux 6.1 & Libbpf 1.1.0
 	   ]
 url {
   src: