NIFI-13494 Remove support for Repository Encryption

[exceptionfactory]

Summary

NIFI-13494 Removes support for repository encryption in framework repository implementations.

As described in the associated Jira issue, the current repository encryption implementation has several structural issues, including the use of Java Object serialization for metadata, encryption key storage on the file system, and key reuse concerns with AES for large data volumes. Solutions based on operating system support for full-disk encryption, or cloud provider support for volume encryption with externalized keys provide robust alternatives.

Changes include removing the nifi-security-kms module and the nifi-repository-encryption module, as well as removing implementation classes in framework modules.

Tracking

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

Issue Tracking

• [X] Apache NiFi Jira issue created

Pull Request Tracking

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

Pull Request Formatting

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

Verification

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Build

• [X] Build completed using mvn clean install -P contrib-check
  • [X] 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