[BUG] Error message displayed for missing variables despite values being assigned during pipeline execution

[SamvelSimonyan]

Precondition:

• An agent exists with variables, some of which are empty.

Steps to reproduce:

1. Add the agent with empty variables to a pipeline.
2. Assign values to the variables during pipeline setup.
3. Execute the pipeline.

Actual results:

• An error message about missing variables is displayed, even though values were assigned during the current run.

2025-10-09_16h26_59.mp4

Expected results:

• If all variables are provided for the current run, no error message should be displayed, and the pipeline should execute successfully.

Pipeline for test: https://dev.elitea.ai/alita_ui/18/pipelines/all/163?viewMode=owner&name=variable%20check