Remove dev env from contribution (#17014)

Summary of the issue:
The contributing page is a list of central pages for different ways to contribute.
Setting up a dev environment doesn't quite come under "a way to contribute" and is part of the above guide.

Description of development approach
Remove this.

.github/CONTRIBUTING.md

@@ -12,5 +12,4 @@ There are several ways in which you can contribute to the NVDA project:
 - [Testing](../projectDocs/testing/contributing.md)
 - [Translating NVDA](../projectDocs/translating/readme.md)
 - [Code or documentation contributions](../projectDocs/dev/contributing.md)
-- [Setting up a development environment](../projectDocs/dev/contributing.md#overview-of-contribution-process)
 - [Creating add-ons](../projectDocs/dev/addons.md)