[DOCS] Remove coming tags for release highlights (#76037)

Removes coming tag from release highlights.

Our 7.x and 8.x docs already have a "preliminary docs" advisory until they're released.
This coming tag duplicates that message. Removing it creates an unneeded chore at release.

This also replaces an outdated coming tag for component template API redirects.

docs/reference/redirects.asciidoc

@@ -826,7 +826,7 @@ See <<ccs-gateway-seed-nodes>> and <<ccs-min-roundtrips>>.
 [role="exclude",id="indices-component-templates"]
 === Component template APIs
 
-coming::[7.x]
+See <<index-templates-apis,index template APIs>>.
 
 [role="exclude",id="modules-indices"]
 === Indices module

docs/reference/release-notes/highlights.asciidoc

@@ -1,8 +1,6 @@
 [[release-highlights]]
 == What's new in {minor-version}
 
-coming::[{minor-version}]
-
 Here are the highlights of what's new and improved in {es} {minor-version}!
 
 For detailed information about this release, see the <<es-release-notes>> and