Remove internal non-collapsing lookup

We can't accurately track "origin miss" vs. "pop miss" without knowing
the backend. We want to encourage lookups to be completed (i.e.
transactional lookups) so we can provide accurate CHR metrics.

This function is not exposed outside of internal/, and is not used by
the public API; so, remove it.

Author: cceckman-at-fastly

internal/abi/fastly/httpcache_guest.go

@@ -218,43 +218,6 @@ type HTTPCacheHandle struct {
 	h httpCacheHandle
 }
 
-// witx:
-//
-//	;;; Perform a cache lookup based on the given request without participating in request
-//	;;; collapsing.
-//	;;;
-//	;;; The request is not consumed.
-//	(@interface func (export "lookup")
-//	    (param $req_handle $request_handle)
-//	    (param $options_mask $http_cache_lookup_options_mask)
-//	    (param $options (@witx pointer $http_cache_lookup_options))
-//	    (result $err (expected $http_cache_handle (error $fastly_status)))
-//	)
-//
-//go:wasmimport fastly_http_cache lookup
-//go:noescape
-func fastlyHTTPCacheLookup(
-	h requestHandle,
-	mask httpCacheLookupOptionsMask,
-	opts prim.Pointer[httpCacheLookupOptions],
-	cacheHandle prim.Pointer[httpCacheHandle],
-) FastlyStatus
-
-func HTTPCacheLookup(req *HTTPRequest, opts *HTTPCacheLookupOptions) (*HTTPCacheHandle, error) {
-	var h httpCacheHandle = invalidHTTPCacheHandle
-
-	if err := fastlyHTTPCacheLookup(
-		req.h,
-		opts.mask,
-		prim.ToPointer(&opts.opts),
-		prim.ToPointer(&h),
-	).toError(); err != nil {
-		return nil, err
-	}
-
-	return &HTTPCacheHandle{h: h}, nil
-}
-
 // witx:
 //
 //	;;; Perform a cache lookup based on the given request.