remove server/tar_fs

Tar_fs is superseded by the vfs server.

Fixes #2024

doc/components.txt

@@ -359,10 +359,6 @@ Separate components:
 :'os/src/server/ram_fs':
   A file-system implementation that keeps all data in memory.
 
-:'os/src/server/tar_fs':
-  A read-only file-system implementation that reads data from a TAR archive,
-  which, in turn, is provided by a ROM service.
-
 :'dde_rump/src/server/rump_fs':
   A file-system server that contains various file-systems ported from the
   NetBSD kernel.

doc/porting_guide.txt

@@ -397,7 +397,7 @@ First, we specify the components that need to be built
 
 ! set build_components {
 !   core init drivers/audio drivers/framebuffer drivers/input
-!   drivers/pci drivers/timer server/tar_fs app/dosbox
+!   drivers/pci drivers/timer app/dosbox
 ! }
 ! build $build_components