NIFI-12332 Remove nifi-toolkit-flowfile-repo Module

[exceptionfactory]

Summary

NIFI-12332 Removes the nifi-toolkit-flowfile-repo module containing a command for repairing FlowFile repository endings. The command is not available through any wrapping shell scripts in the toolkit assembly, and is not part of project documentation.

Additional changes include removing the managed dependency version of Netty 3, which is a legacy remnant and duplicative of settings in the root Maven configuration.

Tracking

Please complete the following tracking steps prior to pull request creation.

Issue Tracking

• Apache NiFi Jira issue created

Pull Request Tracking

• Pull Request title starts with Apache NiFi Jira issue number, such as NIFI-00000
• Pull Request commit message starts with Apache NiFi Jira issue number, as such NIFI-00000

Pull Request Formatting

• Pull Request based on current revision of the main branch
• Pull Request refers to a feature branch with one commit containing changes

Verification

Please indicate the verification steps performed prior to pull request creation.

Build

• Build completed using mvn clean install -P contrib-check
  • JDK 21

Licensing

• New dependencies are compatible with the Apache License 2.0 according to the License Policy
• New dependencies are documented in applicable LICENSE and NOTICE files

Documentation

• Documentation formatting appears as expected in rendered files