Fix edge case when combining PEP 695 aliases with typing.Annotated[]

[brentyi]

First PR for issues uncovered by #177.

Type aliases were not being correctly resolved for reading metadata introduced by typing.Annotated:

type AnnotatedBasic = Annotated[int, tyro.conf.arg(name="basic")]

def test_annotated_alias():
    @dataclass(frozen=True)
    class Container:
        a: AnnotatedBasic

    assert tyro.cli(Container, args="--basic 1".split(" ")) == Container(1)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.71%. Comparing base (8828943) to head (c0d7f46).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #178   +/-   ##
=======================================
  Coverage   99.71%   99.71%           
=======================================
  Files          25       25           
  Lines        2080     2080           
=======================================
  Hits         2074     2074           
  Misses          6        6           

Flag	Coverage Δ
unittests	99.71% <100.00%> (ø)

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