Add connectors release notes for 8.18.7 (#134772)

Author: charlotte-hoblik

docs/reference/connector/docs/connectors-release-notes.asciidoc

@@ -53,6 +53,17 @@ PR https://github.com/elastic/connectors/pull/3577[*#3577*] resolves this issue
 
 There are no new features, enhancements, fixes, known issues, or deprecations associated with this release.
 
+[discrete]
+[[es-connectors-release-notes-8-18-7]]
+=== 8.18.7
+
+[discrete]
+[[es-connectors-release-notes-8-18-7-enhancements]]
+==== Enhancements
+
+* Salesforce connector: Reduced API calls during field validation with caching, improving sync performance.
+See https://github.com/elastic/connectors/pull/3668[*PR 3668*].
+
 [discrete]
 [[es-connectors-release-notes-8-18-6]]
 === 8.18.6
@@ -270,4 +281,4 @@ See https://github.com/elastic/connectors/pull/2695[*PR 2695*].
 ==== Bug fixes
 
 * The Dropbox connector now fetches the files from team shared folders.
-See https://github.com/elastic/connectors/pull/2718[*PR 2718*].
+See https://github.com/elastic/connectors/pull/2718[*PR 2718*].