ci(coverage): introduce undocumented feature of codecov uploader to proxy requests

.gitlab-ci.yml

@@ -30,7 +30,7 @@ variables:
   - gpgv codecov.SHA256SUM.sig codecov.SHA256SUM
   - shasum -a 256 -c codecov.SHA256SUM
   - chmod +x codecov
-  - ./codecov -t ${CODECOV_TOKEN}
+  - ./codecov --upstream ${HTTPS_PROXY} --token ${CODECOV_TOKEN}
 
 .install-deps: &install-deps
   - *install-pip-tools