Fix intermittent build errors by removing buildnumber plugin

[npepinpe]

Description

This PR removes the buildnumber plugin which is unmaintained, and was causing intermittent build errors when building the project without first cleaning. As we already package the project version, we don't need this plugin for now. We could consider eventually adding more versioned properties (e.g. git properties), but we should then use a maintained project such as git-commit-id.

Atomix uses the software version when comparing members as part of its membership algorithm - this was previously parsed from the buildnumber, but now was replaced by our standard VersionUtil.

Related issues

closes #7294

Definition of Done

Not all items need to be done depending on the issue and the pull request.

Code changes:

• The changes are backwards compatibility with previous versions
• If it fixes a bug then PRs are created to backport the fix to the last two minor versions. You can trigger a backport by assigning labels (e.g. backport stable/0.25) to the PR, in case that fails you need to create backports manually.

Testing:

• There are unit/integration tests that verify all acceptance criterias of the issue
• New tests are written to ensure backwards compatibility with further versions
• The behavior is tested manually
• The change has been verified by a QA run
• The impact of the changes is verified by a benchmark

Documentation:

• The documentation is updated (e.g. BPMN reference, configuration, examples, get-started guides, etc.)
• New content is added to the release announcement

[pihme]

bors r+

[ghost]

Build succeeded:

• continuous-integration/jenkins/branch

[github-actions]

Backport failed for stable/1.0, because it was unable to cherry-pick the commit(s).

Please cherry-pick the changes locally.

git fetch origin stable/1.0
git worktree add -d .worktree/backport-7403-to-stable/1.0 origin/stable/1.0
cd .worktree/backport-7403-to-stable/1.0
git checkout -b backport-7403-to-stable/1.0
ancref=$(git merge-base 57f56406fbb6f645a828f99fc1baaefc46d6fb2c 97aec3f893a1b7f7ee99b1abf57c63d7f38be391)
git cherry-pick -x $ancref..97aec3f893a1b7f7ee99b1abf57c63d7f38be391