docs(releasing): remove instructions covered by automated tests (#15353)

docs/releasing.md

@@ -54,29 +54,6 @@ In general, Lighthouse should be using the latest version of all of these depend
 Before starting, you should announce to the LH eng channel that you are releasing,
 and that no new PRs should be merged until you are done.
 
-```sh
-# Make pristine folder.
-bash ./core/scripts/release/prepare-pristine.sh
-cd ../lighthouse-pristine
-yarn
-yarn build-all
-
-# Verify the viewer will work.
-yarn serve-viewer
-# Works with v4 report? http://localhost:7333/viewer?gist=7251f9eba409f385e4c0424515fe8009
-# Works with v5 report? http://localhost:7333/viewer?gist=6093e41b9b50c8d642a7e6bbc784e32f
-# Works with v6 report? http://localhost:7333/viewer?gist=94722e917a507feb5371ad51be6c3334
-# Works with v8 report? http://localhost:7333/viewer?gist=18d523b86779185ecfd376d58f891e1d
-# Current production viewer (https://googlechrome.github.io/lighthouse/viewer/) has forward compat with next major LHR?
-
-# Confirm DevTools integration will work: Do some manual testing on a number of sites.
-yarn test-devtools
-yarn open-devtools
-
-# Leave pristine folder.
-cd ../lighthouse
-```
-
 ### Lightrider
 
 There is a cron that rolls the latest Lighthouse to the Lightrider canary feed.