[fix][client] Pattern subscription regression when broker-side evaluation is disabled

[shibd]

Motivation

When EnableBrokerSideSubscriptionPatternEvaluation is set to false, the pattern subscription can't discover newly created topics.

This regression was introduced by PR #21853 and #22854, which removed pattern consumer regularity discovery topic logic:

https://github.com/apache/pulsar/pull/22854/files#diff-779a47f80b0048bab183870ed4c1ecd07ffd538006cf9358e494bee23405d924L154-L159

Modifications

• Rollback to poll mode for topic discovery when watcherFuture returns an exception.
• Remove recheckPatternTaskBackoff as it is unused and does not align with the user-side configuration patternAutoDiscoveryPeriod.
• Remove test code like consumer.getRecheckPatternTimeout().task().run(consumer.getRecheckPatternTimeout()); from the unit tests, because these tests now operate under the premise of the broker actively pushing topic changes.

Verifying this change

• To reproduce and verify this issue, you can run the test testSubscribePatterBrokerDisable.

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete

Matching PR in forked repository

PR in forked repository:

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 74.27%. Comparing base (bbc6224) to head (2d5b6f8).
Report is 983 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #24104      +/-   ##
============================================
+ Coverage     73.57%   74.27%   +0.69%     
+ Complexity    32624    32484     -140     
============================================
  Files          1877     1864      -13     
  Lines        139502   144351    +4849     
  Branches      15299    16464    +1165     
============================================
+ Hits         102638   107212    +4574     
+ Misses        28908    28686     -222     
- Partials       7956     8453     +497     

Flag	Coverage Δ
inttests	26.72% <0.00%> (+2.13%)	⬆️
systests	23.22% <20.00%> (-1.10%)	⬇️
unittests	73.77% <100.00%> (+0.92%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
...ar/client/impl/PatternMultiTopicsConsumerImpl.java	75.53% <100.00%> (-7.93%)	⬇️

... and 1064 files with indirect coverage changes

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