Merge pull request #29453 from vrabaud:persistence

Replace "static inline" by "inline" in headers #29453

This fixes #29436

I also replaced CV_INLINE which can be removed in a later PR.

I can make a similar PR for 4.x if you want.

### Pull Request Readiness Checklist

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- [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/video/src/bgfg_KNN.cpp

@@ -344,7 +344,7 @@ protected:
 #endif
 };
 
-CV_INLINE void
+static inline void
         _cvUpdatePixelBackgroundNP(int x_idx, const uchar* data, int nchannels, int m_nN,
         uchar* m_aModel,
         uchar* m_nNextLongUpdate,
@@ -395,7 +395,7 @@ CV_INLINE void
     };
 }
 
-CV_INLINE int
+static inline int
         _cvCheckPixelBackgroundNP(const uchar* data, int nchannels,
         int m_nN,
         uchar* m_aModel,

modules/video/src/bgfg_gaussmix2.cpp

@@ -477,7 +477,7 @@ struct GMM
 // shadow detection performed per pixel
 // should work for rgb data, could be useful for gray scale and depth data as well
 // See: Prati,Mikic,Trivedi,Cucchiara,"Detecting Moving Shadows...",IEEE PAMI,2003.
-CV_INLINE bool
+static inline bool
 detectShadowGMM(const float* data, int nchannels, int nmodes,
                 const GMM* gmm, const float* mean,
                 float Tb, float TB, float tau)