recipes.cfg: update all branches to main
recipes.cfg: update all branches to main

All repositories have main branch and it's default branch

R=d05609f027dc667cc37492b1dc1bdea5d60fa82a@chromium.org

Change-Id: I1206574901124012254948095c5a3450b8449517
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2939020
Commit-Queue: Josip Sokcevic <4606aec58cba917397ff2e4738f995e4758694f8@google.com>
Auto-Submit: Josip Sokcevic <4606aec58cba917397ff2e4738f995e4758694f8@google.com>
Reviewed-by: Edward Lesmes <d05609f027dc667cc37492b1dc1bdea5d60fa82a@chromium.org>

CoherentLabs/depot_tools,CoherentLabs/depot_tools