Use main branch from calibreapp/image-actions

Signed-off-by: yubiuser <[email protected]>

Author: yubiuser

.github/workflows/calibreapp-image-actions.yml

@@ -19,6 +19,6 @@ jobs:
         uses: actions/[email protected]
 
       - name: Compress Images
-        uses: calibreapp/image-actions@1.1.0 # TODO: if they start using a tag like v1, switch to that
+        uses: calibreapp/image-actions@main # Their latest tag is > 4 years old and the README says to use main
         with:
           githubToken: ${{ secrets.GITHUB_TOKEN }}