more simplify workflow

Author: arunkannawadi

.github/workflows/ci.yml

@@ -60,7 +60,7 @@ jobs:
         if: env.IMAGE_CHANGED == 'true'
         run: |
           pip install matplotlib
-          fits2bitmap --stretch asinh --percent 99  -o reference/RomanWAS_new/images/truth/Roman_WAS_truth_J129_12909_4.png reference/RomanWAS_new/images/truth/Roman_WAS_truth_J129_12909_4.fits.gz
+          fits2bitmap --stretch asinh --percent 99 -o reference/RomanWAS_new/images/truth/Roman_WAS_truth_J129_12909_4.png reference/RomanWAS_new/images/truth/Roman_WAS_truth_J129_12909_4.fits.gz
 
       - name: Overwrite reference with new image
         if: env.IMAGE_CHANGED == 'true'
@@ -76,9 +76,11 @@ jobs:
             mv -v output/RomanWAS_new/truth/Roman_WAS_index_J129_12909_4.txt reference/RomanWAS_new/truth/Roman_WAS_index_J129_12909_4.txt
           fi
 
-          echo "reference/ is changed; pushing updates"
-          git add reference
-          git commit -m "Update reference"
-          git checkout ${BRANCH_NAME}
-          git pull --rebase
-          git push origin HEAD:${BRANCH_NAME}
+          if git diff --exit-code; then
+              echo "reference/ is unchanged; no action needed"
+          else
+              echo "reference/ is changed; pushing updates"
+              git add reference
+              git commit -m "Update reference"
+              git push
+          fi