Hopefully begin uploading coverage again (#778)

Author: kshyatt

.github/workflows/UnitTests.yml

@@ -66,6 +66,13 @@ jobs:
         Pkg.develop(path="lib/MPIPreferences")
 
     - uses: julia-actions/julia-runtest@latest
+    - uses: julia-actions/julia-processcoverage@v1
+    - uses: codecov/codecov-action@v3
+      with:
+        files: lcov.info
+    - uses: julia-actions/julia-uploadcoveralls@v1
+      env:
+        COVERALLS_TOKEN: ${{ secrets.COVERALLS_TOKEN }}
 
   test-openmpi-jll:
     timeout-minutes: 20