chore(redis): Drop support for < 4.2

[sentrivana]

Drop support for redis-py<4.2:

• remove redis cluster legacy (it was moved directly into redis-py in 4.1)
• remove deprecated max_data_size integration option
• remove conditional patching of async client and pipeline -- just patch always (they're available from 4.2+)
• use the Redis class instead of StrictRedis (which is just an alias)

[github-actions]

Codecov Results 📊

✅ 94850 passed | ⏭️ 5479 skipped | Total: 100329 | Pass Rate: 94.54% | Execution Time: 343m 33s

📊 Comparison with Base Branch

Metric	Change
Total Tests	📉 -5072
Passed Tests	📉 -4072
Failed Tests	—
Skipped Tests	📉 -1000

All tests are passing successfully.

✅ Patch coverage is 100.00%. Project has 2318 uncovered lines.
✅ Project coverage is 90.23%. Comparing base (base) to head (head).

Coverage diff

@@            Coverage Diff             @@
##          main       #PR       +/-##
==========================================
+ Coverage    89.96%    90.23%    +0.27%
==========================================
  Files          193       185        -8
  Lines        24955     23716     -1239
  Branches      9004      8586      -418
==========================================
+ Hits         22448     21398     -1050
- Misses        2507      2318      -189
- Partials      1437      1380       -57

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