build(deps-dev): bump @swc/core from 1.15.18 to 1.15.21

Bumps [@swc/core](https://github.com/swc-project/swc/tree/HEAD/packages/core) from 1.15.18 to 1.15.21.
- [Release notes](https://github.com/swc-project/swc/releases)
- [Changelog](https://github.com/swc-project/swc/blob/main/CHANGELOG.md)
- [Commits](https://github.com/swc-project/swc/commits/v1.15.21/packages/core)

---
updated-dependencies:
- dependency-name: "@swc/core"
  dependency-version: 1.15.21
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

package-lock.json

@@ -59,7 +59,7 @@
     "devDependencies": {
         "@biomejs/biome": "2.4.8",
         "@swc-node/register": "1.11.1",
-        "@swc/core": "1.15.18",
+        "@swc/core": "1.15.21",
         "@types/node": "25.5.0",
         "@types/sprintf-js": "1.1.4",
         "@types/validator": "13.15.10",