refactor: read the fbneo version from version.h

FBNeo bumps src/burn/version.h without tagging: the scraper wrote the
last tag, v1.0.0.02, while the source said 1.0.0.03. It now reads the
header the way the libretro core prints it. The merge no longer writes
core_version: the hashes come from finalburnneo/FBNeo's tip, which the
libretro/FBNeo pin does not name, so the version stays the one
version_basis reads at that pin. A MAME release profile is written with
its version_basis.

scripts/scraper/mame_hash_scraper.py

@@ -467,6 +467,13 @@ def release_profile(
         "source_commit": source_commit,
         "upstream_commit": upstream_commit,
         "core_version": version,
+        # Where profile_sync reads it again: the makefile of the libretro/mame
+        # tree the platform builds, at source_commit.
+        "version_basis": {
+            "kind": "file",
+            "path": "makefile",
+            "pattern": '#define BARE_BUILD_VERSION "([^"]+)"',
+        },
         "display_name": f"Arcade (MAME {version})",
         "cores": cores,
         "built_by": built_by,