Give organisation members access to organisation feeds (#33508)

Currently the organisation feed only includes items for public
repositories (for non-administrators). This pull requests adds
notifications from private repositories to the organisation-feed (for
accounts that have access to the organisation).

Feed-items only get shown for repositories where the users team(s)
should have access to, this filtering seems to get done by some existing
code.

Needs some tests, but am unsure where/how to add them.

Before:

![image](https://github.com/user-attachments/assets/8b63f430-227a-4b19-ad1a-f6f5175de301)

After:

![image](https://github.com/user-attachments/assets/b439ce0e-4946-421c-a399-421806c7a6d8)

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

tests/integration/api_repo_file_get_test.go

@@ -44,8 +44,6 @@ func TestAPIGetRawFileOrLFS(t *testing.T) {
 			reqLFS := NewRequest(t, "GET", "/api/v1/repos/user2/repo1/media/"+lfs)
 			respLFS := MakeRequestNilResponseRecorder(t, reqLFS, http.StatusOK)
 			assert.Equal(t, testFileSizeSmall, respLFS.Length)
-
-			doAPIDeleteRepository(httpContext)
 		})
 	})
 }