fix changelog, again

Author: not-napoleon

docs/changelog/126623.yaml

@@ -17,7 +17,7 @@ breaking:
      considerable space improvement for this use case.
 
      Users can opt out of this behavior on a per-field basis by setting
-     `synthetic_source_keep: all` on the field.
+     `synthetic_source_keep` to `all` on the field.
 
   impact: By default, normalized keyword fields in synthetic source
      indices will no longer return the non-normalized value in the source.

rest-api-spec/src/yamlRestTest/resources/rest-api-spec/test/mget/90_synthetic_source.yml

@@ -58,7 +58,6 @@ keyword with normalizer:
   - requires:
       - cluster_features: "mapper.keyword.keyword_normalizer_synthetic_source"
       - reason: "Behavior changed in #126623"
-
   - do:
       indices.create:
         index: test-keyword-with-normalizer