Pagination: do not add ?{page,per_page} parameters for list endpoints only supporting ?since`

[gr2m]

Follow up to https://github.com/octokit/rest.js/issues/1684#issuecomment-617998848

Example, but there are many

• endpoint scope: Repos
• endpoint name: List public repositories
• route: GET /repositories
• documentation URL: https://developer.github.com/v3/repos/#list-public-repositories

We can look for this note:

Note: Pagination is powered exclusively by the since parameter. Use the Link header to get the URL for the next page of repositories.

Current specification

routes/openapi/api.github.com/operations/repos/list-public.json

Lines 27 to 38 in 661f84e

	{
	"name": "per_page",
	"description": "Results per page (max 100)",
	"in": "query",
	"schema": { "type": "integer", "default": 30 }
	},
	{
	"name": "page",
	"description": "Page number of the results to fetch.",
	"in": "query",
	"schema": { "type": "integer", "default": 1 }
	}

I expected

per_page and page parameters should not be present