nix: add support to build with GCC

Signed-off-by: Amneesh Singh <natto@weirdnatto.in>

flake.lock

@@ -1,23 +1,60 @@
 {
   "nodes": {
+    "flake-parts": {
+      "inputs": {
+        "nixpkgs-lib": "nixpkgs-lib"
+      },
+      "locked": {
+        "lastModified": 1693611461,
+        "narHash": "sha256-aPODl8vAgGQ0ZYFIRisxYG5MOGSkIczvu2Cd8Gb9+1Y=",
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "rev": "7f53fdb7bdc5bb237da7fefef12d099e4fd611ca",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "type": "github"
+      }
+    },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1694911158,
-        "narHash": "sha256-5WENkcO8O5SuA5pozpVppLGByWfHVv/1wOWgB2+TfV4=",
+        "lastModified": 1695318763,
+        "narHash": "sha256-FHVPDRP2AfvsxAdc+AsgFJevMz5VBmnZglFUMlxBkcY=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "46423a1a750594236673c1d741def4e93cf5a8f7",
+        "rev": "e12483116b3b51a185a33a272bf351e357ba9a99",
         "type": "github"
       },
       "original": {
         "owner": "nixos",
-        "ref": "master",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs-lib": {
+      "locked": {
+        "dir": "lib",
+        "lastModified": 1693471703,
+        "narHash": "sha256-0l03ZBL8P1P6z8MaSDS/MvuU8E75rVxe5eE1N6gxeTo=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "3e52e76b70d5508f3cec70b882a29199f4d1ee85",
+        "type": "github"
+      },
+      "original": {
+        "dir": "lib",
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
         "repo": "nixpkgs",
         "type": "github"
       }
     },
     "root": {
       "inputs": {
+        "flake-parts": "flake-parts",
         "nixpkgs": "nixpkgs"
       }
     }