Update docs/ci.md

Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>

docs/ci.md

@@ -60,7 +60,7 @@ free-threaded wheels.
 
 If your project depends on Cython or the NumPy C API, you will need to install a
 Cython nightly wheel in the build, as the newest stable release of Cython cannot
-generate code that will compile under the free-threaded build Cython 3.1.0 and
+generate code that will compile under the free-threaded build. Cython 3.1.0 and
 NumPy 2.1.0 will be or are the first stable releases to support free-threaded
 python. See [the project tracker](tracking.md) for more detailed information
 about projects you may depend on.