ruff

b95fcfbf - [ty] Stop scanning a package after its first legacy namespace declaration (#29885)

[ty] Stop scanning a package after its first legacy namespace declaration (#29885) ## Summary Stop scanning a package initializer once ty recognizes a legacy namespace declaration. The resolver examines only module-level statements and accepts the existing `pkgutil.extend_path` and `pkg_resources.declare_namespace` forms. On the large parser fixture, the declaration check used the following instruction counts. These cover the top-level scan and pattern matching, excluding the calls to obtain and load the parsed module. | Declaration in `__init__.py` | Top-level statements | Visitor (before) | Iterator (after) | Reduction | | --- | ---: | ---: | ---: | ---: | | First statement | 113 | 2,595 | 454 | 2,141 (82.5%) | | Absent | 112 | 3,189 | 1,290 | 1,899 (59.5%) | All three paired runs produced the same counts. The full `ty check` used 0.004% fewer instructions with the declaration first. ## Test Plan The legacy namespace and partial stub package import mdtests passed.