docs: Difference in permission behavior between Tasklist V1 and V2 APIs for CREATE_PROCESS_INSTANCE on PROCESS_DEFINITION

[esraagamal6]

Description:
When the CREATE_PROCESS_INSTANCE permission is granted on the PROCESS_DEFINITION resource type, Tasklist V1 and V2 APIs show different behaviors:

• Tasklist V1 API:
  The user can see the process on Tasklist when CREATE_PROCESS_INSTANCE is granted.
  This is because the V1 API request uses:

• Tasklist V2 API:
  The user cannot see the process on Tasklist with only CREATE_PROCESS_INSTANCE permission.
  V2 instead searches for processes using READ_PROCESS_DEFINITION permission.

This difference leads to inconsistent user experiences depending on which Tasklist API version is used.

tasklistV1.mov

tasklistV2.1.mov

Expected behavior:
The permission requirements and resulting visibility of processes on Tasklist should be clearly documented for both V1 and V2 APIs.

Proposed documentation updates:

• Add clarification to the Tasklist API Versions page](https://docs.camunda.io/docs/next/components/tasklist/api-versions/).

References:
slack thread

related to:
#6477