Move api check to just against main.

Then we don't need to track breaks, we explicit allow them when merging.

.github/workflows/build.yml

@@ -109,13 +109,11 @@ jobs:
  working-directory: main
  run: make compile-tests PROTOC=../protobuf/cmake_build/protoc
 
- api-breakage-since-last-release:
- name: Api Breakage Compared to Last Release
+ api-breakage:
+ name: Api Breakage Compared to main branch
  # Only on pull requests
  if: github.event_name == 'pull_request'
  runs-on: ubuntu-latest
- # Don't fail since we're actively revisit breaking changes on `main`
- continue-on-error: true
  container:
  # Test on the latest Swift release. This could run on all the support
  # Swift versions, but that doesn't seem worth it until there are Swift
@@ -130,13 +128,7 @@ jobs:
  # https://github.com/actions/checkout/issues/766
  run: git config --global --add safe.directory ${GITHUB_WORKSPACE}
  - name: Check for API breaking changes
- # Since descriptor.proto is generated and exposed, any changes upstream
- # can result in things that would count as breaking changes, the allowlist
- # is used to those won't count in this test.
- run: |
- LAST_TAG=$(git describe --abbrev=0 --tags)
- echo "Checking for breaks against the tag: ${LAST_TAG}"
- swift package diagnose-api-breaking-changes "${LAST_TAG}" --breakage-allowlist-path known_api_breaks.txt
+ run: swift package diagnose-api-breaking-changes origin/main
 
  sanitizer_testing:
  # Using older ubuntu image due to issue with newer linux kernel images. When