Is there an easy way to remove the data-preserver-spaces span from blocks?

I converted a page from Classic to Guttenberg and now all the blocks have this span in them:

<p><span data-preserver-spaces="true">...</span></p> 

This means that all the blocks appear on a grey background, which makes it harder to edit, see links, etc.

I know how to edit the HTML and remove the <span> tag like so:


but over 100 blocks, that’s definitely tedious. Is there a way to do that automatically? (like a "clear all formatting" like I’ve see in other editors?)

Here is an example of the effect I’m talking about:

enter image description here

Note that it also happens when text is Italic or Bold or some other such format (which I think is also annoying).