Allow modifying nextRelease from plugins

[tsvetomir]

New feature motivation

Currently, plugins cannot modify the nextRelease object due to the deep cloning of context.

This prevents customization scenarios like custom version suffixes (https://github.com/semantic-release/semantic-release/issues/2446), zero as a major version (https://github.com/semantic-release/semantic-release/issues/1507), and release notes filtering.

New feature description

Allow verifyRelease and generateNotes and other plugins to modify the context.nextRelease fields.

New feature implementation

Removing the cloneDeep call seems sufficient, but may reduce the plugin isolation.

An alternative plugin pipeline configuration could also work.