Revert "Ignore Coveralls errors for now"

Because the upstream issue with Coveralls has been resolved.

This reverts commit 7053edc.

.github/workflows/build.yaml

@@ -115,7 +115,6 @@ jobs:
         format: lcov
         flag-name: linux-${{ matrix.env.cc }}-${{ matrix.qt }}
         parallel: true
-      continue-on-error: true
     - name: Build AppImage
       run: cmake --build "$RUNNER_TEMP" --target cli-appimage
     - name: Upload build artifacts
@@ -244,7 +243,6 @@ jobs:
         format: lcov
         flag-name: mac-${{ matrix.env.cc }}-${{ matrix.qt }}
         parallel: true
-      continue-on-error: true
     - name: Make app bundle
       run: macdeployqt "$RUNNER_TEMP/src/cli/dokit.app" -dmg -verbose=2
     - name: Upload artifacts
@@ -475,7 +473,6 @@ jobs:
       uses: coverallsapp/github-action@v2
       with:
         parallel-finished: true
-      continue-on-error: true
 
   update-tests-on-doc-branch:
     runs-on: ubuntu-latest