[BUG] Pypi stats badge shows invalid due to 429 rate limit exceeded

Describe the bug
Pypi stats badge on SQL-CLI README always show invalid due to 429 rate limit error. And I believe it's coming from upstream Pypistats, which is a project not well maintained.

https://github.com/crflynn/pypistats.org/issues/42

We should consider alternative: https://pepy.tech/project/opensearchsql

To Reproduce
Steps to reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

Or for query issues:

1. Create the index with test documents by 'POST ...'
2. Run the query 'SELECT ...'
3. See error

Expected behavior
A clear and concise description of what you expected to happen.

Plugins
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Screenshots
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Host/Environment (please complete the following information):

• OS: [e.g. iOS]
• Version [e.g. 22]

Additional context
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Start in the SQL-CLI README and inspect the current PyPI stats badge URL, then review the linked Pypistats issue and the proposed pepy.tech alternative. Done means the README badge no longer shows the 429-related invalid state and renders valid project statistics.