feat: allow conditional revalidation for QUERY requests (v4)

[Cherry]

Identical to #7366 but targeting the v4 branch as requested at #7365 (comment). Below is a copy of that PR's description:

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req.fresh only performed weak freshness validation for GET and HEAD, so responses to QUERY requests never returned 304 Not Modified even when the client sent a matching If-None-Match. This extends the method guard to include QUERY.

-  // GET or HEAD for weak freshness validation only
-  if ('GET' !== method && 'HEAD' !== method) return false;
+  // GET, HEAD, or QUERY for weak freshness validation only
+  if ('GET' !== method && 'HEAD' !== method && 'QUERY' !== method) return false;

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As far as I can tell, QUERY is a safe, idempotent, cacheable method whose responses explicitly support conditional revalidation, as per https://datatracker.ietf.org/doc/rfc10008/, so it should behave like GET/HEAD here.

[bjohansebas]

LGTM!