chore(deps): update dependency @actions/core to v3 (#50)

This PR contains the following updates:

| Package | Change | [Age](https://docs.renovatebot.com/merge-confidence/) | [Confidence](https://docs.renovatebot.com/merge-confidence/) |
|---|---|---|---|
| [@actions/core](https://github.com/actions/toolkit/tree/main/packages/core) ([source](https://github.com/actions/toolkit/tree/HEAD/packages/core)) | [`2.0.3` → `3.0.1`](https://renovatebot.com/diffs/npm/@actions%2fcore/2.0.3/3.0.1) | ![age](https://developer.mend.io/api/mc/badges/age/npm/@actions%2fcore/3.0.1?slim=true) | ![confidence](https://developer.mend.io/api/mc/badges/confidence/npm/@actions%2fcore/2.0.3/3.0.1?slim=true) |

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### Release Notes

<details>
<summary>actions/toolkit (@&#8203;actions/core)</summary>

### [`v3.0.1`](https://github.com/actions/toolkit/blob/HEAD/packages/core/RELEASES.md#301)

- Bump `undici` from `6.23.0` to `6.24.1` [#&#8203;2348](https://github.com/actions/toolkit/pull/2348)

### [`v3.0.0`](https://github.com/actions/toolkit/blob/HEAD/packages/core/RELEASES.md#300)

- **Breaking change**: Package is now ESM-only
  - CommonJS consumers must use dynamic `import()` instead of `require()`

</details>

---

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Co-authored-by: Timo Behrendt <t.behrendt@t00n.de>
Reviewed-on: #50
Reviewed-by: t.behrendt <2+t.behrendt@noreply.localhost>
Co-authored-by: Renovate Bot <renovate@t00n.de>
Co-committed-by: Renovate Bot <renovate@t00n.de>

jest.config.js

@@ -3,6 +3,9 @@ module.exports = {
   testEnvironment: "node",
   roots: ["<rootDir>/src"],
   testMatch: ["**/*.spec.ts"],
+  moduleNameMapper: {
+    "^@actions/core$": "<rootDir>/src/__mocks__/actions-core.ts",
+  },
   transform: {
     "^.+\\.ts$": "ts-jest",
   },