Console Error: When using Tab component in combination with a label and an icon the console throws "pseudo class :first-child is potentially unsafe"

[RunRanger]

By using Icon Tabs with label the following error will appear in the console twice:

The pseudo class ":first-child" is potentially unsafe when doing server-side rendering. Try changing it to ":first-of-type".

eg.:
<Tabs value={value} onChange={handleChange} aria-label="icon label tabs example">
    <Tab icon={<PhoneIcon />} label="Calls" />
</Tabs>

If you remove the label or icon attribute of the component, the error won't appear anymore.

This error also appears in the example of the official mui-documentation about IconLabelTabs:
https://codesandbox.io/s/zhmxj?file=/demo.tsx

Expected Behavior 🤔

No error or warning should appear in the console.

Steps to Reproduce 🕹

1. Open the sandbox of the MUI-Documentation about Icon-Tabs with labels or create a Icon-Label Tabs scenario by yourself
   https://codesandbox.io/s/zhmxj?file=/demo.tsx
2. Open the console

Your Environment 🌎

I'm using the latest @mui-version
"@mui/icons-material": "^5.0.0"
"@mui/lab": "*"
"@mui/material": "^5.0.0"
"@mui/styles": "^5.0.0"

Browser: Chrome Version 93.0.4577.82

[mnajdova]

Duplicate of #24894