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/validate_site.py

@@ -264,7 +264,7 @@ def validate_site(site: Path, config_path: Path) -> list[str]:
 
 
 def main() -> None:
-    parser = argparse.ArgumentParser(description=__doc__)
+    parser = argparse.ArgumentParser(allow_abbrev=False, description=__doc__)
     parser.add_argument("--site-dir", default="site")
     parser.add_argument("--config", default="mkdocs.yml")
     parser.add_argument("--max-errors", type=int, default=100)