Fix typo

CHANGELOG.md

@@ -11,7 +11,7 @@ Users may notice changes in inferred binary neutron star masses after updating t
 - Make sure quantities that need to be conserved between dynesty iterations are class-level attributes (!1225).
 - Fix massive memory usage in post-processing calculation of SNRs (!1227).
 - Update value for the solar mass (!1229).
-- Make `scikit-learn` and explicit dependence of `bilby[GW]` (!1230).
+- Make `scikit-learn` an explicit dependence of `bilby[GW]` (!1230).
 
 ## [2.0.0] 2023-02-29
 Version 2.0.0 release of Bilby