Remove usages of npm bin

[pradeepnschrodinger]

Description

npm bin has been removed in npm v9 and above.
See v9 docs:

npm bin has been removed (use npx or npm exec to execute binaries)

Motivation and Context

Some of our scripts still reference npm bin (see #708), so it causes failures.
This fixes #708.

How Has This Been Tested?

Test locally by running npm run site-dev-server and npm run site-build.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.

[pradeepnschrodinger]

I believe this the npm bin path was added so that the commands below (like webpack) can be executed.

So I initially planned on using npx or npm exec to execute them, but it turns out that these are no longer required.

As per the docs for npm run:

In addition to the shell's pre-existing PATH, npm run adds node_modules/.bin to the PATH provided to scripts. Any binaries provided by locally-installed dependencies can be used without the node_modules/.bin prefix.

[AmanGupta2708]

LGTM

[pradeepnschrodinger]

Released with v2.0.4.