[RHOAIENG-26066] bump TrustyAI image transformers in manifests too

This is a followup of the recent image update to propagate this upgrade
also into the image manifest metadata.

Author: jstourac

manifests/base/jupyter-trustyai-notebook-imagestream.yaml

@@ -26,7 +26,7 @@ spec:
           [
             {"name": "JupyterLab","version": "4.2"},
             {"name": "TrustyAI", "version": "0.6"},
-            {"name": "Transformers", "version": "4.49"},
+            {"name": "Transformers", "version": "4.50"},
             {"name": "Datasets", "version": "3.4"},
             {"name": "Accelerate", "version": "1.5"},
             {"name": "Torch", "version": "2.6"},