feat(ci): remove codecov step from tox since performed in GA

There is no need to perform the non-working `codecov` step via `tox` since we now have a Github Actions step that performs it.

.github/workflows/testing.yml

@@ -102,7 +102,7 @@ jobs:
       - name: Test with tox
         run: tox -e ${TOX_VENV}
         env:
-          TOX_VENV: ${{ format('{0}-{1}', matrix.tox-env, 'gevent-eventlet-sasl,codecov') }}
+          TOX_VENV: ${{ format('{0}-{1}', matrix.tox-env, 'gevent-eventlet-sasl') }}
           ZOOKEEPER_VERSION: ${{ matrix.zk-version }}
           # TODO: can be removed once tests for ZK 3.4 are removed
           ZOOKEEPER_PREFIX: "${{ !contains(matrix.zk-version, '3.4') && 'apache-' || '' }}"

tox.ini

@@ -29,7 +29,6 @@ extras =
     sasl: sasl
 deps =
     sasl: kerberos
-    codecov: codecov
 allowlist_externals =
     {toxinidir}/ensure-zookeeper-env.sh
     {toxinidir}/init_krb5.sh
@@ -40,9 +39,6 @@ commands =
 
 [testenv:build]
 
-[testenv:codecov]
-commands = - codecov -e TOX_VENV,ZOOKEEPER_VERSION
-
 [testenv:pep8]
 basepython = python3
 extras = alldeps