fix: valgrind-detected after-freeing access of PyMethodDef (macOS Python 3.9.0 segfaults) (#2576)

* Check if valgrind-detected after-freeing access of PyMethodDef causes macOS Python 3.9 segfaults

* fix: only apply leak on 3.9.0

* fix: faster check

* fix: better naming thanks to @bstaletic

Co-authored-by: Henry Schreiner <henryschreineriii@gmail.com>

.github/workflows/ci.yml

@@ -70,12 +70,6 @@ jobs:
             python: pypy3
             arch: x64
 
-            # TODO: renable
-            # Currently segfaults on macOS Python 3.9
-          - runs-on: macos-latest
-            python: 3.9
-            arch: x64
-
     name: "🐍 ${{ matrix.python }} • ${{ matrix.runs-on }} • ${{ matrix.arch }} ${{ matrix.args }}"
     runs-on: ${{ matrix.runs-on }}