Remove deprecated instrumentation module - java.completable-future-jdk8

[kbford56]

Description

Remove a previously deprecated instrumentation module - java.completable-future-jdk8 - since the underlying library/framework/server is no longer actively supported.

Acceptance Criteria

Removal of the instrumentation module and associated tests.

Design Consideration/Limitations

Need to ensure that all remaining tests pass.

Dependencies

N/A

Additional context

N/A

[workato-integration[bot]]

https://new-relic.atlassian.net/browse/NR-186281

[jasonjkeller]

https://github.com/newrelic/newrelic-java-agent/pull/1640

[kbford56]

Pausing temporarily