Bump tsdown from 0.18.4 to 0.19.0

Bumps [tsdown](https://github.com/rolldown/tsdown) from 0.18.4 to 0.19.0.
- [Release notes](https://github.com/rolldown/tsdown/releases)
- [Commits](rolldown/tsdown@v0.18.4...v0.19.0)

---
updated-dependencies:
- dependency-name: tsdown
  dependency-version: 0.19.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

package-lock.json

@@ -37,7 +37,7 @@
   "devDependencies": {
     "@biomejs/biome": "^2.3.11",
     "expect": "^30.2.0",
-    "tsdown": "^0.18.4",
+    "tsdown": "^0.19.0",
     "typescript": "^5.9.3"
   },
   "engines": {