Fix parsing of the is_master attribute in the URL

[JackiLin]

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Description of change

Fixed the parsing of the is_master attribute in the Redis URL.
When the Redis URL is 'redis://redis-master/1?is_master=0', it is supposed to find the slave node of redis-master for read operations. However, since is_master was parsed as '0' and not correctly interpreted as False, it failed to use the slave node.
I encountered this issue when trying to implement read-write separation using SentinelConnectionPool.

---

Note

Low Risk
Low risk: narrow change to URL query parsing plus a targeted regression test; behavior only changes when is_master is provided in the connection URL.

Overview
Fixes URL query parsing so the is_master option is type-cast via to_bool (e.g., is_master=0 becomes False) when building connection pools from from_url, enabling Sentinel pools to correctly target replica nodes for read operations.

Adds a regression test in tests/test_connection_pool.py covering from_url behavior when specifying the master/replica selector in the query string.

^{Written by Cursor Bugbot for commit 9f15d0a. This will update automatically on new commits. Configure here.}

[vladvildanov]

@JackiLin Thanks for you contribution! I would ask you to provide a test case

[JackiLin]

@JackiLin Thanks for you contribution! I would ask you to provide a test case

Is it OK to add test cases like this

[github-actions]

This pull request has been automatically marked as stale due to inactivity.
It will be closed in 30 days if no further activity occurs.

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

[petyaslavova]

Hi @JackiLin,
I tried to complete this PR, but it seems that I don't have write permissions to your branch.
The fixed test looks like this:

        def test_ismaster_querystring(self):
                pool = redis.ConnectionPool.from_url("redis://localhost/1?is_master=0")
                assert pool.connection_class == redis.Connection
                assert pool.connection_kwargs == {
                    "host": "localhost",
                    "db": 1,
                    "is_master": False,
                }
                pool = redis.ConnectionPool.from_url("redis://localhost/1?is_master=false")
                assert pool.connection_class == redis.Connection
                assert pool.connection_kwargs == {
                    "host": "localhost",
                    "db": 1,
                    "is_master": False,
                }

Can you also fix the linters?
Thanks!