Remove RTCIceCredentialType dictionary

[wbamberg]

This PR removes the RTCIceCredentialType dictionary, which is only used in a single place, and folds its content into the one place where it was used. Part of #3196.

[github-actions]

Preview URLs

• https://pr13915.content.dev.mdn.mozit.cloud/en-US/docs/Mozilla/Firefox/Releases/68
• https://pr13915.content.dev.mdn.mozit.cloud/en-US/docs/Web/API/RTCIceServer/credentialType
• https://pr13915.content.dev.mdn.mozit.cloud/en-US/docs/Web/API/RTCIceServer

Flaws

Note! 2 documents with no flaws that don't need to be listed. 🎉

URL: /en-US/docs/Mozilla/Firefox/Releases/68
Title: Firefox 68 for developers
on GitHub
Flaw count: 6

• macros:
  • /en-US/docs/Web/CSS/linear-gradient() redirects to /en-US/docs/Web/CSS/gradient/linear-gradient()
  • /en-US/docs/Web/CSS/radial-gradient() redirects to /en-US/docs/Web/CSS/gradient/radial-gradient()
  • /en-US/docs/Web/CSS/repeating-radial-gradient() redirects to /en-US/docs/Web/CSS/gradient/repeating-radial-gradient()
  • /en-US/docs/Web/API/SVGElement/focus does not exist
  • /en-US/docs/Web/API/MouseEvent/mozPressure does not exist
• broken_links:
  • Can't resolve /en-US/docs/Mozilla/Firefox_for_Android

External URLs

URL: /en-US/docs/Mozilla/Firefox/Releases/68
Title: Firefox 68 for developers
on GitHub

No new external URLs

---

URL: /en-US/docs/Web/API/RTCIceServer
Title: RTCIceServer
on GitHub

No new external URLs

---

URL: /en-US/docs/Web/API/RTCIceServer/credentialType
Title: RTCIceServer.credentialType
on GitHub

No new external URLs

[teoli2003]

Yes! 👍

[teoli2003]

Let's remove these!