fix: close response body in http strategy (testcontainers#718)

* fix: close response body in http strategy

From to the documentation:
> If the returned error is nil, the Response will contain a non-nil body
which the user is expected to close.

Failed requests (due to wrong response or status code) were leaving
open connections.
Close the response body according to the documentation.

* lint: assign error to empty var

wait/http.go

@@ -217,9 +217,11 @@ func (ws *HTTPStrategy) WaitUntilReady(ctx context.Context, target StrategyTarge
 				continue
 			}
 			if ws.StatusCodeMatcher != nil && !ws.StatusCodeMatcher(resp.StatusCode) {
+				_ = resp.Body.Close()
 				continue
 			}
 			if ws.ResponseMatcher != nil && !ws.ResponseMatcher(resp.Body) {
+				_ = resp.Body.Close()
 				continue
 			}
 			if err := resp.Body.Close(); err != nil {