[Bug] Use `pnpm` when building TS worker from source

[THardy98]

The Typescript SDK has transitioned from npm to pnpm for build scripts (see: temporalio/sdk-typescript#1793)

When building the TS worker from source (i.e. when version is a path), we use npm:

		// Have to build the local repo
		if st, err := os.Stat(filepath.Join(options.Version, "node_modules")); err != nil || !st.IsDir() {
			// Only install dependencies, avoid triggerring any post install build scripts
			cmd := exec.CommandContext(ctx, "npm", "ci", "--ignore-scripts")
			...

			// Build the SDK, ignore the unused `create` package as a mostly insignificant micro optimisation.
			cmd = exec.CommandContext(ctx, "npm", "run", "build", "--", "--ignore", "@temporalio/create")
			...
		}

npm ci fails because it expects package-lock.json but now that we use pnpm, we have pnpm-lock.yaml

We should fix this to use pnpm instead of npm