Fix: Treat __annotate__ functions as library code in Python 3.14+ (#1988)

* Initial plan

* Add special handling for __annotate__ functions in Python 3.14+

Co-authored-by: rchiodo <19672699+rchiodo@users.noreply.github.com>

* Add Python version check for __annotate__ special handling

Co-authored-by: rchiodo <19672699+rchiodo@users.noreply.github.com>

* Fix remaining trailing whitespace

Co-authored-by: rchiodo <19672699+rchiodo@users.noreply.github.com>

* Add clarifying comment about __annotate__ name reservation

Co-authored-by: rchiodo <19672699+rchiodo@users.noreply.github.com>

* Fix ruff error: remove unused 'stop' variable in test

Co-authored-by: rchiodo <19672699+rchiodo@users.noreply.github.com>

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Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: rchiodo <19672699+rchiodo@users.noreply.github.com>