[ty] Preserve recursive structure in Annotated values

[charliermarsh]

Summary

We now terminate inference when an Annotated value recursively wraps its own inferred type:

from typing import Annotated, reveal_type
from ty_extensions._internal import TypeOf

value = int
while True:
    value = Annotated[TypeOf[value], "metadata"]
    reveal_type(value)

We preserve the Annotated wrapper when simplifying the recursive type, so inference can recognize the cycle and stop expanding it.

Addresses the runtime Annotated reproducer in astral-sh/ty#3837.

[astral-sh-bot]

Typing conformance results

No changes detected ✅

Current numbers

The percentage of diagnostics emitted that were expected errors held steady at 98.24%. The percentage of expected errors that received a diagnostic held steady at 98.24%. The number of fully passing files held steady at 134/146.

[astral-sh-bot]

Memory usage report

Memory usage unchanged ✅

[astral-sh-bot]

ecosystem-analyzer results

No diagnostic changes detected ✅

Flaky changes detected. This PR summary excludes flaky changes; see the HTML report for details.

Full report with detailed diff (timing results)

[codspeed]

Merging this PR will not alter performance

✅ 176 untouched benchmarks
⏩ 60 skipped benchmarks¹

---

_{Comparing charlie/ty-3837-investigation (160e6dd) with main (030c500)}

Footnotes

1. 60 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩