fix: avoid instantiating a connection on _repr__

[robertosantamaria-scopely]

Pull Request check-list

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• Do tests and lints pass with this change?
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• Is the new or changed code fully tested?
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Description of change

Changing the __repr__ methods in connection pool classes to avoid instantiating a connection object just to have its string representation.

[Copilot]

Pull Request Overview

This PR refines the connection pool’s string representation by avoiding the instantiation of a connection within repr methods. Key changes include:

• Updating repr in both synchronous and asynchronous connection implementations to prevent side effects.
• Adjusting tests to match the updated repr output format.
• Modifying URL-based connection tests to include an explicit database parameter.

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
tests/test_connection_pool.py	Updated expected repr strings for ConnectionPool in TCP and Unix socket scenarios.
tests/test_asyncio/test_connection_pool.py	Similar repr string updates for the async ConnectionPool tests.
redis/connection.py	Revised repr to assemble connection kwargs without instantiating a new connection.
redis/asyncio/connection.py	Similar updates to repr for the async connection implementation.