ci: Drop travis_fold feature as Travis CI is no longer used

ci/test_run_all.sh

@@ -7,7 +7,6 @@
 export LC_ALL=C.UTF-8
 
 set -o errexit; source ./ci/test/00_setup_env.sh
-set -o errexit; source ./ci/test/03_before_install.sh
 set -o errexit; source ./ci/test/04_install.sh
 set -o errexit; source ./ci/test/05_before_script.sh
 set -o errexit; source ./ci/test/06_script_a.sh