Remove redundant -webkit-prefixed CSS properties

[foolip]

What type of issue is this?

Incorrect support data (example: BrowserX says "86" but support was added in "40")

What information was incorrect, unhelpful, or incomplete?

https://github.com/mdn/browser-compat-data/pull/21621 added many -webkit-prefixed CSS properties (yay!) but a few of them are duplicates of unprefixed properties already in BCD, like hyphenate-character. Let's merge those.

What browsers does this problem apply to, if applicable?

No response

What did you expect to see?

We only need to represent non-standard webkit-prefixed properties that don't have any other entry in BCD.

Did you test this? If so, how?

N/A

Can you link to any release notes, bugs, pull requests, or MDN pages related to this?

No response

Do you have anything more you want to share?

No response

MDN URL

No response

MDN metadata

No response

[foolip]

A burndown list:

• [x] -webkit-hyphenate-character (https://github.com/mdn/browser-compat-data/pull/22887)
• [ ] -webkit-initial-letter (https://github.com/mdn/browser-compat-data/pull/24201)
• [ ] -webkit-mask-composite
• [ ] -webkit-text-decoration-skip
• [ ] -webkit-user-modify