Remove dead code in the Meson build system

Identified in NixOS#11224 (comment)

Co-Authored-By: Robert Hensing <robert@roberthensing.nl>

scripts/meson.build

@@ -1,5 +1,3 @@
-# configures `scripts/nix-profile.sh.in` (and copies the original to the build directory).
-# this is only needed for tests, but running it unconditionally does not hurt enough to care.
 configure_file(
   input : 'nix-profile.sh.in',
   output : 'nix-profile.sh',
@@ -8,13 +6,6 @@ configure_file(
   }
 )
 
-# https://github.com/mesonbuild/meson/issues/860
-configure_file(
-  input : 'nix-profile.sh.in',
-  output : 'nix-profile.sh.in',
-  copy : true,
-)
-
 foreach rc : [ '.sh', '.fish', '-daemon.sh', '-daemon.fish' ]
   configure_file(
     input : 'nix-profile' + rc  + '.in',