fix: refuse abbreviated flags in every script

argparse completed a prefix into the only flag starting with it:
slots.py --emulator read profiles from a directory named after the
emulator and reported nothing, and pipeline.py --all built every pack
variant. Every parser now refuses an abbreviation.

scripts/split_pack.py

@@ -219,6 +219,7 @@ def _size(text: str) -> int:
 
 def main() -> int:
     parser = argparse.ArgumentParser(
+        allow_abbrev=False,
         description="Split packs over the release asset limit into ZIP parts"
     )
     parser.add_argument("target", type=Path, help="a pack, or a directory of packs")