Regenerate schema after merging main (drop stale placeholders)

Pick up #5588's dropShadowingPlaceholders so cli.json descriptions
(e.g. gen_ai_compute_task) flow into the schema instead of being shadowed
by stale PLACEHOLDER markers. Also restore 0644 mode on the tagging files
that genkit marked executable.

Co-authored-by: Isaac

Author: pietern

.github/workflows/tagging.yml

@@ -892,8 +892,6 @@ resources:
               "description": |-
                 PLACEHOLDER
             "gen_ai_compute_task":
-              "description": |-
-                PLACEHOLDER
               "$fields":
                 "compute":
                   "description": |-