Restore thinc requirement

setup.cfg

@@ -30,6 +30,10 @@ include_package_data = true
 python_requires = >=3.7
 install_requires =
     numpy>=2.0.0,<3.0.0
+    # We have to require thinc for setup, so we may as well
+    # include it as an install requirement (we're locked to
+    # the version we build against regardless)
+    thinc>=8.3.0,<9.0.0
 setup_requires = 
     numpy>=2.0.0,<3.0.0
     thinc>=8.3.0,<9.0.0