Merge pull request #25686 from Kumataro:fix25674

Suppress build warnings for GCC14 #25686

Close #25674

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [x] The PR is proposed to the proper branch
- [x] There is a reference to the original bug report and related work
- [ ] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [ ] The feature is well documented and sample code can be built with the project CMake

modules/dnn/src/tensorflow/tf_importer.cpp

@@ -260,7 +260,7 @@ const tensorflow::AttrValue& getLayerAttr(const tensorflow::NodeDef &layer, cons
     return layer.attr().at(name);
 }
 
-#if defined(__GNUC__) && (__GNUC__ == 13)
+#if defined(__GNUC__) && (__GNUC__ >= 13)
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wdangling-reference"
 #endif

modules/dnn/src/torch/torch_importer.cpp

@@ -902,7 +902,7 @@ struct TorchImporter
             {
                 readTorchTable(scalarParams, tensorParams);
 
-                float power;
+                float power = 1.0f;
                 if (nnName == "Square") power = 2.0f;
                 else if (nnName == "Sqrt") power = 0.5f;
                 else if (nnName == "Power") power = scalarParams.get<float>("pow", 1.0f);