Fix duplicate HTMX component parameters

[erikgaas]

Summary

• Remove duplicate indicator and replace_url entries from hx_attrs.
• Add a notebook test requiring the exported attribute list to contain unique names.
• Regenerate components.pyi without duplicate parameters.

Why

tools/mk_pyi.py expands hx_attrs directly into every component signature. Duplicate list entries therefore generate duplicate hx_indicator and hx_replace_url parameters, which makes the stub invalid for mypy.

Runtime component signatures already deduplicate these names, so this change does not alter rendered HTML or supported arguments.

Fixes #908.
Fixes #529.

Checks

• nbdev-test --path nbs/api/01_components.ipynb
• Parsed fasthtml/components.pyi with ast.parse
• Confirmed no generated signature repeats hx_indicator or hx_replace_url
• Confirmed a fresh interpreter still renders both attributes correctly