chore: update identity organization

[Kerruba]

This pull request updates the repository references for the Camunda Identity project in the GitHub Actions workflows. All references to the old repository name camunda-cloud/identity are changed to the new repository name camunda/identity to ensure that release generation and release workflows interact with the correct repository.

Repository reference updates:

• Updated installation_retrieval_payload and gh release download commands in .github/workflows/release-generation.yaml to use camunda/identity instead of camunda-cloud/identity. [1] [2]
• Updated installation_retrieval_payload and gh release download commands in .github/workflows/release.yaml to use camunda/identity instead of camunda-cloud/identity. [1] [2]

NOTE: This must be merged once the transfer is completed

Checkout for context:

• camunda/team-infrastructure#934