Merge pull request matplotlib#24535 from meeseeksmachine/auto-backport-of-pr-24514-on-v3.6.x

Backport PR matplotlib#24514 on branch v3.6.x (Fix potential issue in contour)

Author: QuLogic

lib/matplotlib/contour.py

@@ -1362,6 +1362,7 @@ def find_nearest_contour(self, x, y, indices=None, pixel=True):
         d2min = np.inf
         conmin = None
         segmin = None
+        imin = None
         xmin = None
         ymin = None