nix: use nixpkgs app2unit

update flake inputs

flake.lock

@@ -1,30 +1,7 @@
 {
   "nodes": {
-    "app2unit": {
-      "inputs": {
-        "nixpkgs": [
-          "nixpkgs"
-        ]
-      },
-      "locked": {
-        "lastModified": 1752640923,
-        "narHash": "sha256-jcoNgqOaD7wuoYg6y+BXuCHueDzJ7gjR7RdFKHBNg2A=",
-        "owner": "soramanew",
-        "repo": "app2unit",
-        "rev": "d0159c1d7090f8563db6bedd153cb8168628b06d",
-        "type": "github"
-      },
-      "original": {
-        "owner": "soramanew",
-        "repo": "app2unit",
-        "type": "github"
-      }
-    },
     "caelestia-shell": {
       "inputs": {
-        "app2unit": [
-          "app2unit"
-        ],
         "caelestia-cli": [],
         "nixpkgs": [
           "nixpkgs"
@@ -32,11 +9,11 @@
         "quickshell": "quickshell"
       },
       "locked": {
-        "lastModified": 1754283125,
-        "narHash": "sha256-963FwoaeO99FZaYWNPNxYj2eLd1DAeJleZOO6cRMyDo=",
+        "lastModified": 1754708216,
+        "narHash": "sha256-F9p2mCUqxmeZf7fkzO0xifCVa2ZFpJFKhLGV03hSl50=",
         "owner": "caelestia-dots",
         "repo": "shell",
-        "rev": "c1b844b8571b6a5f9bde2490f841e76a0c8efaac",
+        "rev": "a2a0bb5866b18ea4d66fdbdf089e0ca25b222b9e",
         "type": "github"
       },
       "original": {
@@ -47,11 +24,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1753939845,
-        "narHash": "sha256-K2ViRJfdVGE8tpJejs8Qpvvejks1+A4GQej/lBk5y7I=",
+        "lastModified": 1754498491,
+        "narHash": "sha256-erbiH2agUTD0Z30xcVSFcDHzkRvkRXOQ3lb887bcVrs=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "94def634a20494ee057c76998843c015909d6311",
+        "rev": "c2ae88e026f9525daf89587f3cbee584b92b6134",
         "type": "github"
       },
       "original": {
@@ -84,7 +61,6 @@
     },
     "root": {
       "inputs": {
-        "app2unit": "app2unit",
         "caelestia-shell": "caelestia-shell",
         "nixpkgs": "nixpkgs"
       }