Document the local Godot 4.7.2 toolchain

Record the upgraded 4.7.2 binary, the retained 4.3 backup and the matching
export templates. Keep the project/CI baseline at 4.3 and note that 4.7.2
verified import, tests, the session smoke and a Linux export. Hide the
4.7-generated per-script UID sidecars from this clone only.

docs/RELEASING.md

@@ -15,7 +15,8 @@ time you export, either:
   `Godot_v4.3-stable_export_templates.tpz` contents into
   `~/.local/share/godot/export_templates/4.3.stable/`.
 
-Verify with:
+The templates must match the editor binary you use locally. CI pins Godot 4.3;
+the local development machine uses 4.7.2 with its matching templates. Verify with:
 
 ```bash
 godot --headless --export-release "Linux" build/gig-line-smoke.x86_64