want to get rid off some https://fonts.gstatic.com requests
If you are using Google Fonts, then you cannot. Gstatic.com is a domain that Google owns and uses to serve static content. See this answer on SuperUser.
PageSpeed Insights gives me a warning about "Make sure all text remains visible while loading the web fonts"
I hope you have read the documentation.
When using Google Fonts, add the &display=swap
parameter to the end of the Google Fonts URL.
The good news is, following the instructions on Google Fonts will generally handle things for you.

Continue reading iff the above could not satisfy you
For further speedups and/or customization (e.g. reducing the number of preconnects), this is how I handle the issue.
Suppose I want to use the font Comfortaa
.
<link href="https://fonts.googleapis.com/css2?family=Comfortaa&display=swap" rel="stylesheet">
Instead of linking the remote CSS file at https://fonts.googleapis.com/css2?family=Comfortaa&display=swap, I visit the URL, download the CSS file to the server and link to that instead.
This gets rid of the delay caused while establishing connections to fonts.googleapis.com
.
Warning:
The CSS files provided by Google Fonts may be changed in future.
It is your responsibility to update those files when modified by Google Fonts.