It was only shown when Search Provider was set to Google, but the
same key is also needed for Google embeddings in Semantic Search
(Advanced tab) — a completely separate feature from web search. A
user who only wanted Google for embeddings had no way to find where
to enter the key. Now always visible under General → Web Search, with
a caption clarifying both uses; Search Engine ID stays conditional
since it's web-search-specific. Also pointed the Semantic Search tab's
"no providers available" hint at the same location.
rune
4d65ab7703