[Task]: Deprecate Java8

[Abacn]

What needs to happen?

This should be done after #31677

Require Build Beam with Java11+. Therefore enable to use newer gradle plugins that already dropped Java8 support. The released Beam artifact should still keep Java8 compatibility.

Issue Priority

Priority: 2 (default / most normal work should be filed as P2)

Issue Components

• Component: Python SDK
• Component: Java SDK
• Component: Go SDK
• Component: Typescript SDK
• Component: IO connector
• Component: Beam YAML
• Component: Beam examples
• Component: Beam playground
• Component: Beam katas
• Component: Website
• Component: Spark Runner
• Component: Flink Runner
• Component: Samza Runner
• Component: Twister2 Runner
• Component: Hazelcast Jet Runner
• Component: Google Cloud Dataflow Runner

[Abacn]

Sent a discussion on beam dev: https://lists.apache.org/thread/w5lf2tg1nlk77so2p39cqphr1gqbh72s

[Abacn]

#31896 : gcs-connector 3 dropped Java 8 support

[Abacn]

This comment tracks current blockers (some test has to run on Java8):

• [Failing Test]: Java Samza runner tests failing on Java11 #32208 Java Samza runner tests failing on Java11
• [Failing Test]: SparkVersionTest 3.4.0+ fails on Java11 #32207 SparkVersionTest 3.4.0+ fails on Java11
• [Failing Test]: Tests involve hive-exec has to run on Java8 #32189 Tests involve hive-exec has to run on Java8