fix: fixed compile error (eigen vs. opencv)

Signed-off-by: Kenzo Lobos-Tsunekawa <[email protected]>

sensor/tag_based_pnp_calibrator/src/tag_based_pnp_calibrator.cpp

@@ -12,6 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#include <Eigen/Dense>  // note: this header must come before <opencv2/core/eigen.hpp>
 #include <opencv2/core.hpp>
 #include <opencv2/core/eigen.hpp>
 #include <rclcpp/time.hpp>