fix: record each platform's own list version

install/<platform>.json wrote the constant "1.0" as the version of the
list it was built from. The manifest now carries the version the platform
YAML records, and generate_pack refuses a YAML without one.

inherits: no longer passes a parent's version to a child: Lakka was
published as RetroArch v1.22.2 in its manifest, pack name and site page.
lakka.yml records v6.1, the Lakka-LibreELEC tag its target list is read
at. The MiSTer scraper refuses a BiosDB without a timestamp instead of
writing an empty version.

A pack's manifest.json records list_version, so an install from the pack
alone knows it too. Manifests regenerated twice and compared: only
version and generated changed.

install/romm.json

@@ -5,8 +5,8 @@
   "categorized": true,
   "platform": "romm",
   "display_name": "RomM",
-  "version": "1.0",
-  "generated": "2026-10-26T22:11:28Z",
+  "version": "5.4.0",
+  "generated": "2026-10-27T10:27:58Z",
   "base_destination": "bios",
   "detect": [
     {