nushell: remove redundant abbreviations option

Nushell abbreviations are regular config settings, so users can already express them through programs.nushell.settings.abbreviations. Keep test coverage on that native path instead of maintaining a second option.

tests/modules/programs/nushell/config-expected.nu

@@ -13,6 +13,8 @@ load-env {
     "PROMPT_COMMAND": ({|| "> "})
 }
 
+$env.config.abbreviations.gs = "git status"
+$env.config.abbreviations.ll = "ls -l"
 $env.config.display_errors.exit_code = false
 $env.config.hooks.pre_execution = [
     ({|| "pre_execution hook"})
@@ -29,8 +31,3 @@ let config = {
 alias "ll" = ls -a
 alias "multi word alias" = cd -
 alias "z" = __zoxide_z
-
-$env.config.abbreviations = {
-    "gs": "git status"
-    "ll": "ls -l"
-}

tests/modules/programs/nushell/example-settings.nix

@@ -38,12 +38,11 @@
       "z" = "__zoxide_z";
     };
 
-    abbreviations = {
-      "gs" = "git status";
-      "ll" = "ls -l";
-    };
-
     settings = {
+      abbreviations = {
+        "gs" = "git status";
+        "ll" = "ls -l";
+      };
       show_banner = false;
       display_errors.exit_code = false;
       hooks.pre_execution = [ (lib.hm.nushell.mkNushellInline ''{|| "pre_execution hook"}'') ];