Emitter should not use TSX to run installation script

[lmazuel]

We need emitters to have as low dependencies as possible, and "tsx" is convenient, but not necessary. We could write our scripts in TypeScript, compile them in JS at release time, and ship that (not sure the details, I'm sure a JS expert could provide help). But we shouldn't rely on "typescript" being installed. It ends up like this for 3P people:

[msyyc]

After discussion, we will remove dependency for tsx.