ci(coverage): make checks informational on release branches (#541)

Make codecov status checks informational on `main`/`release/**` branches
so they don't block Craft publishing, while keeping patch coverage
blocking on PRs.

## Changes

- **`codecov.yml`**: Add `coverage.status` config with `project` always
informational and `patch` blocking by default (for PRs)
- **`ci.yml`**: Add `sed` step on push events to flip `patch` to
informational on `main`/`release/**`

## Behavior

| Context | `codecov/project` | `codecov/patch` |
|---------|-------------------|-----------------|
| PR | informational | **blocking** |
| `main` / `release/**` push | informational | informational |

Uses `getsentry/codecov-action`'s `informational` config option. Since
the action has no per-branch config support, the CI workflow
conditionally edits `codecov.yml` via `sed` on push events before
running the action.

Author: BYK

.github/workflows/ci.yml

@@ -179,6 +179,10 @@ jobs:
         run: bun run test:isolated --coverage --coverage-reporter=lcov --coverage-dir=coverage-isolated
       - name: Merge Coverage Reports
         run: bun run script/merge-lcov.ts coverage/lcov.info coverage-isolated/lcov.info > coverage/merged.lcov
+      - name: Make coverage checks informational on release branches
+        if: github.event_name == 'push'
+        run: |
+          sed -i 's/informational: false/informational: true/' codecov.yml
       - name: Coverage Report
         uses: getsentry/codecov-action@main
         with: