fmf: Force checking out node_modules/
fmf: Force checking out node_modules/

During upstream PR testing, there is some existing, but outdated
node_modules/, and it's completely unclear where it's coming from. Check
out the known good node_modules/ more aggressively.

cockpit-project/cockpit,cockpit-project/cockpit,cockpit-project/cockpit,martinpitt/cockpit,martinpitt/cockpit,martinpitt/cockpit,martinpitt/cockpit,martinpitt/cockpit,cockpit-project/cockpit,cockpit-project/cockpit