Revert "{facts,vars}/generator: also setup /proc"

This reverts commit 943f836997a54f8b0d40665b555034b8ac5a5da4.

This currently fails in nix sandbox builds... figure this out later.

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

@@ -49,7 +49,6 @@ def bubblewrap_cmd(generator: str, facts_dir: Path, secrets_dir: Path) -> list[s
             "--ro-bind", "/nix/store", "/nix/store",
             "--tmpfs",  "/usr/lib/systemd",
             "--dev", "/dev",
-            "--proc", "/proc",
             "--bind", str(facts_dir), str(facts_dir),
             "--bind", str(secrets_dir), str(secrets_dir),
             "--unshare-all",

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

@@ -41,7 +41,6 @@ def bubblewrap_cmd(generator: str, tmpdir: Path) -> list[str]:
             "--ro-bind", "/nix/store", "/nix/store",
             "--tmpfs",  "/usr/lib/systemd",
             "--dev", "/dev",
-            "--proc", "/proc",
             "--bind", str(tmpdir), str(tmpdir),
             "--unshare-all",
             "--unshare-user",