Fix built-in functions being double-counted as regular tags

[fafouine]

Summary

In scripts/generate_tag_index.py, the regular-tag pattern #(\w+) also matches the name inside a built-in such as #print(). Because #(\w+)\(\) (built-ins) and #(\w+) (regular tags) both scan the same text, #print() was captured by both — so print showed up in the built-ins index and as a regular #print tag, producing duplicate/misleading entries (and its generated print.md page was overwritten).

Fix

After extracting methods and built-ins, drop any regular tag whose name was already captured as a method or built-in:

# The regular-tag pattern (#word) also matches the name inside a
# built-in like #print(), so #print() lands in both built_ins and
# regular_tags. Drop any regular tag whose name was already captured
# as a method or built-in to avoid double-counting.
reserved = set(methods) | set(built_ins)
regular_tags = [tag for tag in regular_tags if tag not in reserved]

Verification

• Reproduced the bug: for a sample containing #print() #len() #.append() #python #Web_Security, the original code returns regular_tags = ['print', 'len', 'python', 'Web_Security'].
• After the fix, regular_tags = ['python', 'Web_Security']; built_ins = ['print', 'len']; methods = ['append', 'split'].
• Ran the full script end-to-end against a sample log file: #print()/#len() now appear only under Built-in Functions and no longer under Tags in tags/index.md. Temporary sample/generated files were removed so this PR contains only the one-file change.

Task & docs

• Notion task: Fix built-in functions being double-counted as regular tags
• Explainer doc: Explainer: Fix built-in functions being double-counted as regular tags