Feature Request: GitHub Action to update Power Platform Environment Variables without solution import

[gadamsettie2]

Currently, updating Power Platform (Dataverse) environment variable values in CI/CD requires importing a solution using the import-solution GitHub Action. This is heavyweight when the only change needed is updating one or more environment variable values.

This issue proposes adding a lightweight GitHub Action (or extending an existing one) that allows direct updates to environment variable values in a target Power Platform environment without importing a solution.