[FLINK-38289] Update to Flink 2.1

[tomncooper]

This PR updates the Flink version to 2.1.0.

The main issue with this update is that Flink has removed (without deprecating first) the stripRowPrefix method from the DataTypeUtilsTest class. So this PR adds that logic into a util class within the connector.

Also note that with the update to Flink 2.1.0 the connector drops support for Python 3.8, I added testing for Python 3.11 but 3.12-cython (2.1 added support for Python 3.12) is not yet available.

[gaborgsomogyi]

Tests are pending.

[gaborgsomogyi]

Please spotless the code

[tomncooper]

Please spotless the code

Believe me I am trying, but running mvn spotless:check locally (with maven 3.8.6 and Java 17) reveals no issues. It appears all the checks are skipped?

[tomncooper]

So the reason it skips it locally is that it is defaulted to that in the connector parent pom. I am not sure what in the ci config overrides that, but I had to manually add the spotless plugin to the build config, and set skip to false, in each child module to get it to run.

[gaborgsomogyi]

Leaving it open for couple of days in order to wait for comments from others.

[davidradl]

@tomncooper looks like you have conflicts

[raphaelauv]

hi @gaborgsomogyi , is there any release planned ?

flink 2.1 and kafka 4.0 are great new features

Thanks

[gaborgsomogyi]

First I need to release Flink 2.1.1 and then we can take a look at this connector...

[jessechencx]

when publish? i not found it in mvnrepository .