fix(deps): update nix-doom-emacs-unstraightened to fix live-usb flake check

Updates nix-doom-emacs-unstraightened from Jan 25 to Jan 31 release,
which fixes the stale doom-intermediates.drv reference that was causing
nixosConfigurations.live-usb to fail flake check.

Closes: x-0cf

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

flake.lock

@@ -47,11 +47,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1769329593,
-        "narHash": "sha256-u5PSA+8TUYF/13ziBcnoE67nkDwpjAdecKh3srcJJm0=",
+        "lastModified": 1769848312,
+        "narHash": "sha256-ggBocPd1L4l5MFNV0Fw9aSGZZO4aGzCfgh4e6hQ77RE=",
         "owner": "nix-community",
         "repo": "emacs-overlay",
-        "rev": "776dc33d735af583a14cc56b406ea658398964a7",
+        "rev": "be0b4f4f28f69be61e9174807250e3235ee11d50",
         "type": "github"
       },
       "original": {
@@ -206,11 +206,11 @@
         "systems": "systems_2"
       },
       "locked": {
-        "lastModified": 1769330679,
-        "narHash": "sha256-X7rw5ouiAYKmbbKLtkEc/Kqcg6DxKgOtgaftzuchy/M=",
+        "lastModified": 1769849328,
+        "narHash": "sha256-BjH1Ge6O8ObN6Z97un2U87pl4POO99Q8RSsgIuTZq8Q=",
         "owner": "marienz",
         "repo": "nix-doom-emacs-unstraightened",
-        "rev": "0c2d527055f448c8856129c6d063535e06aeff4d",
+        "rev": "fc1d7190c49558cdc6af20d7657075943a500a93",
         "type": "github"
       },
       "original": {