Update gemini-pr-review.yml

Author: richabanker

.github/workflows/gemini-pr-review.yml

@@ -32,8 +32,8 @@ jobs:
       - name: Debug diff output
         run: echo "${{ steps.diff.outputs.DIFF }}"
 
-      - name: Set DIFF environment variable
-        run: echo "INPUT_DIFF=${{ steps.diff.outputs.DIFF }}" >> $GITHUB_ENV
+      - name: Base64 encode DIFF
+        run: echo "INPUT_DIFF=$(echo "${{ steps.diff.outputs.DIFF }}" | base64)" >> $GITHUB_ENV
 
       - name: Run Gemini review script
         env: