alter npm version requirement to allow for newer versions

[cwadrupldijjit]

Description:
This changes the npm versions required to allow for later versions, as the versions of NPM and Node required are quite old and in practice, the requirement doesn't seem necessary anymore.

Changes proposed:

• Change npm version string in the package.json to allow for later versions (>=) of npm than just the latest minor version of 2 (^)

Closes #4869

[cwadrupldijjit]

It's looking like a test has failed. The error encountered is:

    ✔ sets cursor
  ✖ "after each" hook
Finished in 29.788 secs / 5.678 secs @ 20:31:41 GMT+0000 (Coordinated Universal Time)
SUMMARY:
✔ 969 tests completed
ℹ 14 tests skipped
✖ 1 test failed
FAILED TESTS:
  ✖ "after each" hook
    Firefox 89.0.0 (Linux 0.0.0)
  TypeError: camera.updateProjectionMatrix is not a function (/tmp/src/core/scene/a-scene.js:9:0 <- /tmp/2b7e5905d191b874557b484c1c0b1981.browserify:55344)
npm ERR! Test failed.  See above for more details.
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! [email protected] test:firefox: `npm test -- --browsers Firefox "--single-run"`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the [email protected] test:firefox script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR!     /home/travis/.npm/_logs/2021-06-07T20_31_42_718Z-debug.log
The command "$CI_ACTION" exited with 1.

What can we do to fix it?

[dmarcos]

Giving this a try. Be aware we might have to revert if there are any issues with newer npm versions. Congrats on your first PR! 🥇