Bump @polkadot/api from 7.12.1 to 7.13.1 in /ts-tests (#410)

Bumps [@polkadot/api](https://github.com/polkadot-js/api/tree/HEAD/packages/api) from 7.12.1 to 7.13.1.
- [Release notes](https://github.com/polkadot-js/api/releases)
- [Changelog](https://github.com/polkadot-js/api/blob/master/CHANGELOG.md)
- [Commits](https://github.com/polkadot-js/api/commits/v7.13.1/packages/api)

---
updated-dependencies:
- dependency-name: "@polkadot/api"
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

ts-tests/package.json

@@ -24,7 +24,7 @@
     "typescript": "^4.6.2"
   },
   "dependencies": {
-    "@polkadot/api": "^7.12.1",
+    "@polkadot/api": "^7.13.1",
     "@polkadot/types": "^7.13.1",
     "dotenv": "^16.0.0",
     "web3": "^1.7.1"