docs: Fix instructions to check if Development.SABIModule was requested (#957)

This fixes instructions originally introduced in 48a879b ("docs: some
updates (#334)", 2023-05-23)

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Henry Schreiner <[email protected]>

Author: 3 people

docs/cmakelists.md

@@ -36,7 +36,7 @@ related to making Python extension modules.
 
 If you are making a Limited API / Stable ABI package, you'll need the
 `Development.SABIModule` component instead (CMake 3.26+). You can use the
-`SKBUILD_LIMITED_API` variable to check to see if it was requested.
+`SKBUILD_SABI_COMPONENT` variable to check to see if it was requested.
 
 <!-- prettier-ignore-start -->
 :::{warning}