Merge pull request #29663 from Prasoon-Bodke:fix/houghlinesp-doc-shape-5.0

samples: fix HoughLines/HoughLinesP Python sample for 5.0 shape change (fixes #29637) - #29663

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Fixes #29637.

OpenCV 5.0 changed vector-backed Mat/OutputArray to true 1D arrays (see 
migration guide: 1D and 0D array semantics). This changes HoughLines/
HoughLinesP Python return shape from (N,1,X) to (N,X), breaking the old 
indexing pattern used in the tutorial sample.

Tested locally against opencv-python 5.0 — script runs without error, 
lines drawn correctly on samples/data/sudoku.png.

samples/python/snippets/houghlines.py

@@ -29,17 +29,17 @@ def main():
 
     if True: # HoughLinesP
         lines = cv.HoughLinesP(dst, 1, math.pi/180.0, 40, np.array([]), 50, 10)
-        a, b, _c = lines.shape
+        a, b = lines.shape
         for i in range(a):
-            cv.line(cdst, (lines[i][0][0], lines[i][0][1]), (lines[i][0][2], lines[i][0][3]), (0, 0, 255), 3, cv.LINE_AA)
+            cv.line(cdst, (lines[i][0], lines[i][1]), (lines[i][2], lines[i][3]), (0, 0, 255), 3, cv.LINE_AA)
 
     else:    # HoughLines
         lines = cv.HoughLines(dst, 1, math.pi/180.0, 50, np.array([]), 0, 0)
         if lines is not None:
-            a, b, _c = lines.shape
-            for i in range(a):
-                rho = lines[i][0][0]
-                theta = lines[i][0][1]
+            num_lines, _ = lines.shape
+            for i in range(num_lines):
+                rho = lines[i][0]
+                theta = lines[i][1]
                 a = math.cos(theta)
                 b = math.sin(theta)
                 x0, y0 = a*rho, b*rho
@@ -57,4 +57,4 @@ def main():
 if __name__ == '__main__':
     print(__doc__)
     main()
-    cv.destroyAllWindows()
+    cv.destroyAllWindows()