Disable coveralls, use julia-specific codecov action

Coveralls is causing the workflow to fail with
"Couldn't find a repository matching this job."

lemurheavy/coveralls-public#1264 (comment)
Not sure what's happening here. I had only just now created a corresponding project on codecov for this repo.

.github/workflows/ci.yml

@@ -37,12 +37,9 @@ jobs:
       - uses: julia-actions/julia-buildpkg@latest
       - uses: julia-actions/julia-runtest@latest
       - uses: julia-actions/julia-processcoverage@v1
-      - uses: codecov/codecov-action@v1
-        with:
-          file: lcov.info
-      - uses: julia-actions/julia-uploadcoveralls@latest
+      - uses: julia-actions/julia-uploadcodecov@latest
         env:
-          COVERALLS_TOKEN: ${{ secrets.COVERALLS_TOKEN }}
+          CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
   docs:
     name: Documentation
     runs-on: ubuntu-latest