iproute: 5.7.0 -> 5.8.0 (#94965)

"The former date based internal versioning (snapshot) is replaced by the
regular version numbering which corresponds to the kernel version." [0]

File changes (additions/removals):
+share/man/man8/ip-mptcp.8.gz
+share/man/man8/tc-gate.8.gz

[0]: https://marc.info/?l=linux-netdev&m=159681449423365

pkgs/os-specific/linux/iproute/default.nix

@@ -5,16 +5,19 @@
 
 stdenv.mkDerivation rec {
   pname = "iproute2";
-  version = "5.7.0";
+  version = "5.8.0";
 
   src = fetchurl {
     url = "mirror://kernel/linux/utils/net/${pname}/${pname}-${version}.tar.xz";
-    sha256 = "088gs56iqhdlpw1iqjwrss4zxd4zbl2wl8s2implrrdajjxcfpbj";
+    sha256 = "0vk4vickrpahdhl3zazr2qn2bf99v5549ncirjpwiy4h0a4izkfg";
   };
 
   preConfigure = ''
     # Don't try to create /var/lib/arpd:
     sed -e '/ARPDDIR/d' -i Makefile
+    # TODO: Drop temporary version fix for 5.8 (53159d81) once 5.9 is out:
+    substituteInPlace include/version.h \
+      --replace "v5.7.0-77-gb687d1067169" "5.8.0"
   '';
 
   outputs = [ "out" "dev" ];