build(deps): bump dependencies to latest versions

- @biomejs/biome 2.5.15 -> 2.6.4
- tsdown 0.23.0 -> 0.23.5
- Point the Biome schema at 2.6.4
- Refresh transitive dependencies in the lockfile

biome.json

@@ -1,5 +1,5 @@
 {
-  "$schema": "https://biomejs.dev/schemas/2.5.15/schema.json",
+  "$schema": "https://biomejs.dev/schemas/2.6.4/schema.json",
   "vcs": {
     "enabled": true,
     "clientKind": "git",

package.json

@@ -44,8 +44,8 @@
     "release": "npm publish"
   },
   "devDependencies": {
-    "@biomejs/biome": "^2.5.15",
-    "tsdown": "^0.23.0",
+    "@biomejs/biome": "^2.6.4",
+    "tsdown": "^0.23.5",
     "typescript": "^7.0.2"
   }
 }