Delete the image_gradient_maps module.

PiperOrigin-RevId: 790496933

Author: llcourage

.github/workflows/ci.yml

@@ -33,7 +33,7 @@ jobs:
     strategy:
       matrix:
         node-version: [18]
-        python-version: ["3.9", "3.10", "3.11"]
+        python-version: ["3.11"]
     defaults:
       run:
         shell: bash -l {0}