rust 1.84, update deps (#48)

- `nix flake update`
- `cargo update`

flake.lock

@@ -2,11 +2,11 @@
   "nodes": {
     "crane": {
       "locked": {
-        "lastModified": 1733286231,
-        "narHash": "sha256-mlIDSv1/jqWnH8JTiOV7GMUNPCXL25+6jmD+7hdxx5o=",
+        "lastModified": 1736566337,
+        "narHash": "sha256-SC0eDcZPqISVt6R0UfGPyQLrI0+BppjjtQ3wcSlk0oI=",
         "owner": "ipetkov",
         "repo": "crane",
-        "rev": "af1556ecda8bcf305820f68ec2f9d77b41d9cc80",
+        "rev": "9172acc1ee6c7e1cbafc3044ff850c568c75a5a3",
         "type": "github"
       },
       "original": {
@@ -23,11 +23,11 @@
         "rust-analyzer-src": "rust-analyzer-src"
       },
       "locked": {
-        "lastModified": 1732689334,
-        "narHash": "sha256-yKI1KiZ0+bvDvfPTQ1ZT3oP/nIu3jPYm4dnbRd6hYg4=",
+        "lastModified": 1736577158,
+        "narHash": "sha256-ngnAENZ+vmzOFgnj0EDtHj22nuH7MQB+EqzUmdbvaqA=",
         "owner": "nix-community",
         "repo": "fenix",
-        "rev": "a8a983027ca02b363dfc82fbe3f7d9548a8d3dce",
+        "rev": "05dcdb02ea657f81b13d99bd0ca36b09d25f4c43",
         "type": "github"
       },
       "original": {
@@ -56,11 +56,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1733212471,
-        "narHash": "sha256-M1+uCoV5igihRfcUKrr1riygbe73/dzNnzPsmaLCmpo=",
+        "lastModified": 1736344531,
+        "narHash": "sha256-8YVQ9ZbSfuUk2bUf2KRj60NRraLPKPS0Q4QFTbc+c2c=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "55d15ad12a74eb7d4646254e13638ad0c4128776",
+        "rev": "bffc22eb12172e6db3c5dde9e3e5628f8e3e7912",
         "type": "github"
       },
       "original": {
@@ -81,11 +81,11 @@
     "rust-analyzer-src": {
       "flake": false,
       "locked": {
-        "lastModified": 1732633904,
-        "narHash": "sha256-7VKcoLug9nbAN2txqVksWHHJplqK9Ou8dXjIZAIYSGc=",
+        "lastModified": 1736517563,
+        "narHash": "sha256-YJ5ajpMsyXITc91ZfnI0Mdocd+tmCFkZ3BLozUkB44M=",
         "owner": "rust-lang",
         "repo": "rust-analyzer",
-        "rev": "8d5e91c94f80c257ce6dbdfba7bd63a5e8a03fa6",
+        "rev": "4f35021ca9a8e7f9ed4344139b9eaf770a2e5725",
         "type": "github"
       },
       "original": {