[fix][io] Only bundle kafka schema registry client

[nicoloboschi]

Fixes #18920

Motivation

Only kafka-schema-registry-client has ASL license and the connector actually needs only it (and serializers, ASL too)

Modifications

• import kafka-schema-registry-client instead of kafka-schema-registry

Documentation

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

[codecov-commenter]

Codecov Report

Merging #18931 (72b8093) into master (3180a4a) will increase coverage by 0.51%.
The diff coverage is 47.91%.

@@             Coverage Diff              @@
##             master   #18931      +/-   ##
============================================
+ Coverage     46.17%   46.69%   +0.51%     
- Complexity    10359    10487     +128     
============================================
  Files           703      703              
  Lines         68845    68858      +13     
  Branches       7382     7383       +1     
============================================
+ Hits          31788    32150     +362     
+ Misses        33448    33089     -359     
- Partials       3609     3619      +10     

Flag	Coverage Δ
unittests	46.69% <47.91%> (+0.51%)	⬆️

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

Impacted Files	Coverage Δ
.../main/java/org/apache/pulsar/PulsarStandalone.java	0.00% <0.00%> (ø)
...broker/intercept/ManagedLedgerInterceptorImpl.java	0.00% <0.00%> (ø)
...va/org/apache/pulsar/broker/service/ServerCnx.java	49.71% <ø> (+2.28%)	⬆️
...va/org/apache/pulsar/client/impl/ConsumerImpl.java	15.09% <0.00%> (-0.04%)	⬇️
...he/pulsar/client/impl/MultiTopicsConsumerImpl.java	22.78% <0.00%> (-0.09%)	⬇️
...va/org/apache/pulsar/client/impl/ProducerImpl.java	16.83% <0.00%> (-0.17%)	⬇️
...nsaction/pendingack/impl/PendingAckHandleImpl.java	52.09% <50.00%> (+0.25%)	⬆️
.../pulsar/broker/service/AbstractBaseDispatcher.java	58.85% <100.00%> (+1.38%)	⬆️
...sistent/PersistentDispatcherMultipleConsumers.java	58.85% <100.00%> (+7.12%)	⬆️
.../apache/pulsar/client/impl/BatchMessageIdImpl.java	67.50% <100.00%> (-4.73%)	⬇️
... and 59 more

[lhotari]

@nicoloboschi @eolivelli Is there a specific reason to stick to the old 5.3.0 schema registry client?

    <kafka.confluent.schemaregistryclient.version>5.3.0</kafka.confluent.schemaregistryclient.version>
    <kafka.confluent.avroserializer.version>5.3.0</kafka.confluent.avroserializer.version>

5.3.0 was released in July 2019. That is ancient.

[eolivelli]

Lgtm

[lhotari]

@nicoloboschi @eolivelli Is there a specific reason to stick to the old 5.3.0 schema registry client?

    <kafka.confluent.schemaregistryclient.version>5.3.0</kafka.confluent.schemaregistryclient.version>
    <kafka.confluent.avroserializer.version>5.3.0</kafka.confluent.avroserializer.version>

5.3.0 was released in July 2019. That is ancient.

@nicoloboschi @eolivelli I've addressed the upgrade in #19010