Reapply "remove nix_shell_legacy"

This reverts commit c5001f19fc.

pkgs/clan-cli/clan_cli/vars/generate.py

@@ -17,7 +17,7 @@ from clan_cli.completions import (
 from clan_cli.errors import ClanError
 from clan_cli.git import commit_files
 from clan_cli.machines.inventory import get_all_machines, get_selected_machines
-from clan_cli.nix import nix_config, nix_shell_legacy, nix_test_store
+from clan_cli.nix import nix_config, nix_shell, nix_test_store
 from clan_cli.vars._types import StoreBase
 
 from .check import check_vars
@@ -84,10 +84,10 @@ def bubblewrap_cmd(generator: str, tmpdir: Path) -> list[str]:
     test_store = nix_test_store()
 
     # fmt: off
-    return nix_shell_legacy(
+    return nix_shell(
         [
-            "nixpkgs#bash",
-            "nixpkgs#bubblewrap",
+            "bash",
+            "bubblewrap",
         ],
         [
             "bwrap",

pkgs/clan-cli/clan_cli/vars/secret_modules/password_store.py

@@ -9,7 +9,7 @@ from tempfile import TemporaryDirectory
 
 from clan_cli.cmd import CmdOut, Log, RunOpts, run
 from clan_cli.machines.machines import Machine
-from clan_cli.nix import nix_shell_legacy
+from clan_cli.nix import nix_shell
 from clan_cli.ssh.upload import upload
 from clan_cli.vars._types import StoreBase
 from clan_cli.vars.generate import Generator, Var
@@ -49,9 +49,7 @@ class SecretStore(StoreBase):
         return Path(self.entry_prefix) / self.rel_dir(generator, name)
 
     def _run_pass(self, *args: str, options: RunOpts | None = None) -> CmdOut:
-        cmd = nix_shell_legacy(
-            packages=["nixpkgs#pass"], cmd=[self._store_backend, *args]
-        )
+        cmd = nix_shell(packages=["pass"], cmd=[self._store_backend, *args])
         return run(cmd, options)
 
     def _set(
@@ -92,8 +90,8 @@ class SecretStore(StoreBase):
         hashes = []
         hashes.append(
             run(
-                nix_shell_legacy(
-                    ["nixpkgs#git"],
+                nix_shell(
+                    ["git"],
                     [
                         "git",
                         "-C",
@@ -120,8 +118,8 @@ class SecretStore(StoreBase):
             if symlink.is_symlink():
                 hashes.append(
                     run(
-                        nix_shell_legacy(
-                            ["nixpkgs#git"],
+                        nix_shell(
+                            ["git"],
                             [
                                 "git",
                                 "-C",