chore(nix): move rustSimple from users.Profpatsch.writers

I think it’s solid enough to use in a wider context.

Change-Id: If53e8bbb6b90fa88d73fb42730db470e822ea182
Reviewed-on: https://cl.tvl.fyi/c/depot/+/3055
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
Reviewed-by: lukegb <lukegb@tvl.fyi>

users/Profpatsch/writers/tests/default.nix

@@ -4,9 +4,6 @@ let
   inherit (depot.users.Profpatsch.writers)
     python3Lib
     python3
-    rustSimple
-    rustSimpleLib
-    rustSimpleBin
     ;
 
   inherit (pkgs)
@@ -44,54 +41,8 @@ let
     assert(test_lib.test() == "test 1 2 3")
   '');
 
-
-  rustTransitiveLib = rustSimpleLib {
-    name = "transitive";
-  } ''
-    pub fn transitive(s: &str) -> String {
-      let mut new = s.to_string();
-      new.push_str(" 1 2 3");
-      new
-    }
-
-    #[cfg(test)]
-    mod tests {
-      use super::*;
-
-      #[test]
-      fn test_transitive() {
-        assert_eq!(transitive("foo").as_str(), "foo 1 2 3")
-      }
-    }
-  '';
-
-  rustTestLib = rustSimpleLib {
-    name = "test_lib";
-    dependencies = [ rustTransitiveLib ];
-  } ''
-    extern crate transitive;
-    use transitive::{transitive};
-    pub fn test() -> String {
-      transitive("test")
-    }
-  '';
-
-  rustWithLib = run (rustSimple {
-    name = "rust-with-lib";
-    dependencies = [ rustTestLib ];
-  } ''
-    extern crate test_lib;
-
-    fn main() {
-      assert_eq!(test_lib::test(), String::from("test 1 2 3"));
-    }
-  '');
-
-
 in depot.nix.utils.drvTargets {
   inherit
     pythonWithLib
-    rustTransitiveLib
-    rustWithLib
     ;
 }