fix: remove BigQuery from Token page (#1153)

## High Level Overview of Change

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Please include a summary/list of the changes.
If too broad, please consider splitting into multiple PRs.
-->
We are moving away from using Google Cloud for the Explorer.
The Explorer is using GCP credential to query top trading pairs data
from this public dataset:
[GitHub - WietseWind/fetch-xrpl-transactions: Fetch (and store) all XRPL
transactions (to a custom
datastore)](https://github.com/WietseWind/fetch-xrpl-transactions)
which has not been maintained recently. It would make sense to remove
this part completely from the token page.

### Type of Change

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Please check relevant options, delete irrelevant ones.
-->

- [x] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to not work as expected)
- [ ] Refactor (non-breaking change that only restructures code)
- [ ] Tests (You added tests for code that already exists, or your new
feature included in this PR)
- [ ] Documentation Updates
- [ ] Translation Updates
- [ ] Release

## Before / After

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If just refactoring / back-end changes, this can be just an in-English
description of the change at a technical level.
If a UI change, screenshots should be included.
-->

Token page will no longer contain `Top Trading Pairs` section.

Author: pdp2121

.env.example

@@ -28,8 +28,3 @@ VITE_DATA_URL=https://data.xrpl.org/v1/network
 # Whether to use ws instead of wss (boolean)
 # Only used locally (the deployed Explorer requires wss)
 VITE_INSECURE_WS=0
-
-#Google Credentials for BigQuery, DO NOT COMMIT THESE
-GOOGLE_APP_PROJECT_ID=
-GOOGLE_APP_PRIVATE_KEY=
-GOOGLE_APP_CLIENT_EMAIL=

README.md

@@ -14,22 +14,6 @@ The project requires node@22. Follow installation instructions on [nodejs.org](h
 
 Make sure to use npm version 8+ by running `npm install -g npm@latest` after you install Node.
 
-### Google BigQuery Setup
-
-This setup is required for the Tokens page of the explorer to function:
-
-1.  [Select or create a Cloud Platform project][projects].
-1.  [Enable the Google BigQuery API][enable_api].
-1.  [Set up authentication with a service account][auth]
-
-Once you have completed these steps and generated the JSON key file, you must populate the following environment variables in the .env file with their corresponding values from the JSON key file:
-
-```
-GOOGLE_APP_PROJECT_ID=your-project-id
-GOOGLE_APP_PRIVATE_KEY=-----BEGIN PRIVATE KEY-----\n...
-GOOGLE_APP_CLIENT_EMAIL=your-client-email
-```
-
 ### Copy example env
 
 `cp .env.example .env`
@@ -102,7 +86,3 @@ When updating translation entires or adding new languages consult the guide [Tra
 - Latest news in [react blog](https://reactjs.org/blog)
 - [React documentation](https://reactjs.org/docs)
 - [How to think in react](https://reactjs.org/docs/thinking-in-react.html) and break down components
-
-[enable_api]: https://console.cloud.google.com/flows/enableapi?apiid=bigquery.googleapis.com
-[projects]: https://console.cloud.google.com/project
-[auth]: https://cloud.google.com/docs/authentication/getting-started