fix: double loading image when placeholder is present

[george-moongroup]

🔗 Linked issue

resolves #1683

❓ fix

• [ ] 📖 Documentation (updates to the documentation or readme)
• [x] 🐞 Bug fix (a non-breaking change that fixes an issue)
• [ ] 👌 Enhancement (improving an existing functionality)
• [ ] ✨ New feature (a non-breaking change that adds functionality)
• [ ] 🧹 Chore (updates to the build process or auxiliary tools and libraries)
• [ ] ⚠️ Breaking change (fix or feature that would cause existing functionality to change)

📚 Description

We resolved an issue where images could load more than once in the NuxtImg component. Previously, when a placeholder image was in use, it triggered a new image load even though the main image had already started loading. The update ensures that if a placeholder is already handled, we avoid loading the image again. This change prevents duplicate network requests and avoids unnecessary load events