ci: fix passing env vars to build scripts

Author: dvarrazzo

.github/workflows/packages.yml

@@ -96,6 +96,7 @@ jobs:
           CIBW_TEST_COMMAND: >-
             export PYTHONPATH={project} &&
             python -c "import tests; tests.unittest.main(defaultTest='tests.test_suite')"
+          CIBW_ENVIRONMENT_PASS_LINUX: LIBPQ_VERSION OPENSSL_VERSION
           CIBW_ENVIRONMENT: >-
             PACKAGE_NAME=psycopg2-binary
             LIBPQ_BUILD_PREFIX=/host/tmp/libpq.build