chore(deps): update dependency robotframework-browser to v20 (#377)

This PR contains the following updates:

| Package | Change | [Age](https://docs.renovatebot.com/merge-confidence/) | [Confidence](https://docs.renovatebot.com/merge-confidence/) |
|---|---|---|---|
| [robotframework-browser](https://github.com/MarketSquare/robotframework-browser) ([changelog](https://github.com/MarketSquare/robotframework-browser/tree/main/docs/releasenotes)) | `==19.15.1` → `==20.0.0` | ![age](https://developer.mend.io/api/mc/badges/age/pypi/robotframework-browser/20.0.0?slim=true) | ![confidence](https://developer.mend.io/api/mc/badges/confidence/pypi/robotframework-browser/19.15.1/20.0.0?slim=true) |

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### Release Notes

<details>
<summary>MarketSquare/robotframework-browser (robotframework-browser)</summary>

### [`v20.0.0`](https://github.com/MarketSquare/robotframework-browser/releases/tag/v20.0.0): Browser library v20.0.0

[Compare Source](https://github.com/MarketSquare/robotframework-browser/compare/v19.15.1...v20.0.0)

Browser library 20.0.0 is a new release with enhancements and bug fixes. There are enhancements to Wait For Request and Get Text keywords, both keywords contains backward incompatible changes. There is bug fix for the Stop Coverage keyword and bug fixes to the library documentation. All issues targeted for Browser library v20.0.0 can be found from the [issue tracker](https://github.com/MarketSquare/robotframework-browser/issues?q=state%3Aclosed%20milestone%3Av20.0.0). Browser library 20.0.0 was released on Sunday June 7, 2026. Browser supports Python 3.10+, Node 22/24 LTS and Robot Framework 6.1+. Library was tested with Playwright 1.60.0

</details>

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Reviewed-on: #377
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requirements.txt

@@ -1,5 +1,5 @@
 robotframework==7.4.2
-robotframework-browser==19.15.1
+robotframework-browser==20.0.0
 robotframework-seleniumlibrary==6.9.0
 urllib3==2.7.0
 psycopg[binary]==3.3.4