chore: remove link to curve button

[linear[bot]]

ZKF-1367 Delete link to "Try with Curve" button from zkSync.io

## 🗒️ Business requirements We're deprecating our integration with Curve because most of our forces is focused on private release of the testnet. Right now we have a task to close zksync.curve.fi with placeholder: [ZKF-1336](https://linear.app/matterlabs/issue/ZKF-1336/suspend-curve-zksync-integration) So because of this we should delete this button from our landing page, just to not mislead user to the not working feature.  ## ✅ Acceptance Criteria * [ ] Button "Try Curve + zkSync testnet" is deleted.

[github-actions[bot]]

Visit the preview URL for this PR (updated for commit 8af55f1):

https://zksync-js-docs--pr204-dr-zkf-1367-delete-l-qruf1w40.web.app

_{(expires Thu, 20 Jan 2022 22:58:25 GMT)}

_{🔥 via Firebase Hosting GitHub Action 🌎}

[linear[bot]]

ZKF-1367 Delete link to "Try with Curve" button from zkSync.io

## 🗒️ Business requirements We're deprecating our integration with Curve because most of our forces is focused on private release of the testnet. Right now we have a task to close zksync.curve.fi with placeholder: [ZKF-1336](https://linear.app/matterlabs/issue/ZKF-1336/suspend-curve-zksync-integration) So because of this we should delete this button from our landing page, just to not mislead user to the not working feature.  ## ✅ Acceptance Criteria * [X] Button "Try Curve + zkSync testnet" is deleted.