Add action may not need to run npm install

[purplecabbage]

When running aio app add action many times package.json is NOT modified, but we still run npm install which takes a around 10 seconds every time.

Expected Behaviour

package.json not modified, npm install NOT run

Actual Behaviour

package.json not modified, npm install IS run

Reproduce Scenario (including but not limited to)

Steps to Reproduce

Platform and Version

Sample Code that illustrates the problem

aio app init
aio app add action // pick generic

Logs taken while reproducing problem

? We are about to create a new sample action that showcases how to access an external API.
How would you like to name this action? generic-6
identical package.json
   create actions/generic-6/index.js
   create test/actions/generic-6.test.js
identical actions/utils.js
identical test/actions/utils.test.js
   create e2e/actions/generic-6.e2e.js


I'm all done. Running npm install for you to install the required dependencies. If this fails, try running the command yourself.
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