Support converging inclusive gateway

[koevskinikola]

Problem you would like to solve

Support for the converging inclusive gateway (i.e. converging OR gateway) is added to Zeebe in https://github.com/camunda/zeebe/pull/12642 as an external contribution. Of course, all the Camunda Platform 8 need to be aligned and support the feature.

If the Modeler doesn't support modeling the converging inclusive gateway for Camunda Platform 8, then our customers cannot use this new feature.

Proposed solution

Please support the converging inclusive gateway for Camunda Platform 8. The behavior is specified in the related Zeebe issue.

• Remove the validation that restricts the number of incoming sequence flows to an inclusive gateway to max 1.

Alternatives considered

• Users can update the XML by hand
• Users can use combinations of XOR and AND gateways to rebuild the OR gateway logic.

Additional context

• https://github.com/camunda/product-hub/issues/364
• https://github.com/camunda/zeebe/issues/10031