sshfs: 3.7.2 -> 3.7.3

https://github.com/libfuse/sshfs/releases/tag/sshfs-3.7.3:
> This is the last release from the current maintainer. SSHFS is now no
> longer maintained or developed. Github issue tracking and pull
> requests have therefore been disabled. The mailing list (see below) is
> still available for use.
>
> If you would like to take over this project, you are welcome to do so.
> Please fork it and develop the fork for a while. Once there has been 6
> months of reasonable activity, please contact [e-mail] and
> I'll be happy to give you ownership of this repository or replace with
> a pointer to the fork.

pkgs/tools/filesystems/sshfs-fuse/default.nix

···
   }
 else
   mkSSHFS {
-    version = "3.7.2";
-    sha256 = "0i0ycgwdxja8313hlkrlwrl85a4ykkyqddgg484jkr4rnr7ylk8w";
+    version = "3.7.3";
+    sha256 = "0s2hilqixjmv4y8n67zaq374sgnbscp95lgz5ignp69g3p1vmhwz";
     platforms = lib.platforms.linux;
   }