Fix nightly QA run for stable/0.26

[korthout]

Description

The QA run can be run against a generation version of choice when running using the Build with parameters. This version specifies which versions of other components to spin up next to Zeebe as part of the Camunda Cloud cluster. For the nightly QA run, a default generation is provided in the Jenkinsfile which is statically defined and not automatically updated.

The currently used generation Zeebe 0.26.1 is no longer available and should be replaced by Zeebe 0.26.4.

This PR fixes the nightly QA runs against the stable/0.26 branch by switching to this newer generation version.

Related issues

closes #7237

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

[korthout]

@pihme please have a look. I'd love to find a better solution to this (i.e. not defining it explicitly in the Jenkinsfile), but I have not yet found how to do it. If you have ideas, please share.

EDIT: It also seems the daily runs are enabled again on both 1.0 and 0.26 which are unaffected by this

[pihme]

bors r+

[ghost]

Build succeeded:

• continuous-integration/jenkins/branch