provision: Avoid spending 2s reinstalling node/npm.
provision: Avoid spending 2s reinstalling node/npm.

Tweaked by tabbott to just check the versions.

Fixes #5184.

brockwhittaker/zulip,jackrzhang/zulip,kou/zulip,rishig/zulip,brockwhittaker/zulip,jackrzhang/zulip,jrowan/zulip,synicalsyntax/zulip,timabbott/zulip,jackrzhang/zulip,kou/zulip,rishig/zulip,rishig/zulip,rht/zulip,eeshangarg/zulip,rht/zulip,timabbott/zulip,punchagan/zulip,eeshangarg/zulip,showell/zulip,synicalsyntax/zulip,hackerkid/zulip,zulip/zulip,brainwane/zulip,shubhamdhama/zulip,dhcrzf/zulip,amanharitsh123/zulip,verma-varsha/zulip,vaidap/zulip,dhcrzf/zulip,vabs22/zulip,amanharitsh123/zulip,punchagan/zulip,Galexrt/zulip,timabbott/zulip,mahim97/zulip,rishig/zulip,vabs22/zulip,amanharitsh123/zulip,tommyip/zulip,andersk/zulip,jackrzhang/zulip,synicalsyntax/zulip,kou/zulip,synicalsyntax/zulip,vabs22/zulip,kou/zulip,dhcrzf/zulip,synicalsyntax/zulip,kou/zulip,andersk/zulip,brainwane/zulip,jrowan/zulip,timabbott/zulip,Galexrt/zulip,mahim97/zulip,Galexrt/zulip,andersk/zulip,mahim97/zulip,timabbott/zulip,zulip/zulip,shubhamdhama/zulip,jackrzhang/zulip,tommyip/zulip,brainwane/zulip,vaidap/zulip,timabbott/zulip,hackerkid/zulip,eeshangarg/zulip,jackrzhang/zulip,vaidap/zulip,hackerkid/zulip,vaidap/zulip,shubhamdhama/zulip,brockwhittaker/zulip,synicalsyntax/zulip,mahim97/zulip,punchagan/zulip,brainwane/zulip,synicalsyntax/zulip,eeshangarg/zulip,vaidap/zulip,jrowan/zulip,rht/zulip,dhcrzf/zulip,brockwhittaker/zulip,shubhamdhama/zulip,tommyip/zulip,Galexrt/zulip,verma-varsha/zulip,kou/zulip,showell/zulip,showell/zulip,eeshangarg/zulip,vaidap/zulip,andersk/zulip,vabs22/zulip,verma-varsha/zulip,tommyip/zulip,vabs22/zulip,tommyip/zulip,tommyip/zulip,zulip/zulip,hackerkid/zulip,rht/zulip,punchagan/zulip,eeshangarg/zulip,showell/zulip,amanharitsh123/zulip,dhcrzf/zulip,showell/zulip,andersk/zulip,jrowan/zulip,brockwhittaker/zulip,brockwhittaker/zulip,showell/zulip,zulip/zulip,jrowan/zulip,mahim97/zulip,brainwane/zulip,rishig/zulip,punchagan/zulip,brainwane/zulip,Galexrt/zulip,brainwane/zulip,andersk/zulip,amanharitsh123/zulip,showell/zulip,rht/zulip,andersk/zulip,shubhamdhama/zulip,jrowan/zulip,dhcrzf/zulip,mahim97/zulip,shubhamdhama/zulip,zulip/zulip,timabbott/zulip,zulip/zulip,jackrzhang/zulip,eeshangarg/zulip,punchagan/zulip,Galexrt/zulip,hackerkid/zulip,Galexrt/zulip,dhcrzf/zulip,rht/zulip,zulip/zulip,tommyip/zulip,shubhamdhama/zulip,amanharitsh123/zulip,vabs22/zulip,verma-varsha/zulip,verma-varsha/zulip,punchagan/zulip,kou/zulip,hackerkid/zulip,verma-varsha/zulip,hackerkid/zulip,rht/zulip,rishig/zulip,rishig/zulip