chore(deps): update flake.lock (#5271)

Flake lock file updates:

• Updated input 'nixpkgs':
    'github:NixOS/nixpkgs/20535e4' (2026-07-18)
  → 'github:NixOS/nixpkgs/335f073' (2026-07-24)
• Updated input 'rust-overlay':
    'github:oxalica/rust-overlay/afacd68' (2026-07-19)
  → 'github:oxalica/rust-overlay/fe21243' (2026-07-26)

flake.lock

@@ -2,11 +2,11 @@
   "nodes": {
     "nixpkgs": {
       "locked": {
-        "lastModified": 1784364478,
-        "narHash": "sha256-CdItYNdYUlm7NxqMVyQKqT2IxTwvapiPuRLWOyHTrbY=",
+        "lastModified": 1784872115,
+        "narHash": "sha256-THPEF2po0fsoH8gNtp+Ae0XFDJH3N/ol7xO3v6VMTJU=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "20535e48e12c86043b577b8518234ff5dbb26957",
+        "rev": "335f0738cb2fa9708f3f428e39d2eae975d1338d",
         "type": "github"
       },
       "original": {
@@ -29,11 +29,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1784438913,
-        "narHash": "sha256-NYF7ZM5ip0u+w1pBFDpIGEbrbgN/wpnLFAmBkWkYMXw=",
+        "lastModified": 1785044261,
+        "narHash": "sha256-ehF/c4fLdgmNu7YXEClnmwhoBYddhYIVoSQpsZoorC4=",
         "owner": "oxalica",
         "repo": "rust-overlay",
-        "rev": "afacd6819d3765a05814ee8e3de74c77d42ac799",
+        "rev": "fe2124391e739e7b3e8720cd8a73f06edd0aceba",
         "type": "github"
       },
       "original": {