GH Actions: version update for codecov action runner (#226)

Yet another predefined action has had a major release.

This is, again, mostly just a change of the Node version used by the action itself (from Node 12 to Node 16).

Refs:
* https://github.com/codecov/codecov-action/releases

Co-authored-by: jrfnl <jrfnl@users.noreply.github.com>

.github/workflows/continuous-integration.yml

@@ -79,7 +79,7 @@ jobs:
       - name: "Run expect tests"
         run: "bashcov --root ./bin -- ./tests/bash-test.sh tests/tests.sh"
       - name: "Publish coverage report to Codecov"
-        uses: "codecov/codecov-action@v2"
+        uses: "codecov/codecov-action@v3"
         with:
           files: "./bin/coverage/codecov-result.json"