Remove Add to Cart button from a product with a vendor code?

Yes you can achieve this in Shopify by hiding or disabling “Buy/Add to cart” button for all products with a specific vendor code. This doesn’t requires manually editing each product. You can handle it via liquid.
Before moving further you must know the exact vendor name as defined in the product settings. After that you need to Edit the code.
Go to Online Store >> Themes >> Edit code
In the Edit Code search for product-template.liquid section. Or it maybe a product.liquid section. It’s vary on the theme that you currently using.
No you need to wrap the Buy button with a condition.
Initial the Buy button should like like this:

<button type="submit" name="add" class="product-form__submit">{{ general.buttons.atc_button 
 t }}</button>

Now replace it with the condition based code:

{% if product.vendor != "VENDOR_CODE" %}
    <button type="submit" name="add" class="product-form__submit">Add to cart</button>
{% else %}
    <p class="text-red-600">Currently unavailable due to supplier change.</p>
{% endif %}

replace the vendor code with the actual code.
I hope this could helps you. If this was helpful then don’t forget to like it.