Chores: Clean usage of `Deno.build.os` for Windows to reduce duplication

[cderv]

We are using a lot Deno.build.os === "windows" though we have cleaner solution for our code.

We have our own wrapper

quarto-cli/src/core/platform.ts

Lines 12 to 14 in 20e6279

	export function isWindows() {
	return Deno.build.os === "windows";
	}

and there is one also in https://deno.land/std@0.166.0/_util/os.ts

I believe this would be beneficial for our code to be simpler with less duplication