CI: Use 'gh release' to upload assets to release (#3187)

Author: seisman

.github/workflows/release-baseline-images.yml

@@ -17,6 +17,10 @@ jobs:
     runs-on: ubuntu-latest
     if: github.repository == 'GenericMappingTools/pygmt'
 
+    permissions:
+      # To write assets to GitHub release
+      contents: write
+
     steps:
     - name: Checkout
       uses: actions/[email protected]
@@ -35,7 +39,6 @@ jobs:
         shasum -a 256 baseline-images.zip
 
     - name: Upload baseline image as a release asset
-      uses: shogo82148/[email protected]
-      with:
-        upload_url: ${{ github.event.release.upload_url }}
-        asset_path: baseline-images.zip
+      run: gh release upload ${{ github.ref_name }} baseline-images.zip
+      env:
+        GH_TOKEN: ${{ github.token }}