convert windows directory slash "\" to posix directory slash "/".

import { assertEquals } from "jsr:@std/assert"

// aliasing our functions for brevity
const eq = assertEquals, fn = pathToPosixPath

eq(fn("C:\\Users/my name\\file.txt"), "C:/Users/my name/file.txt")
eq(fn("~/path/to/file.txt"), "~/path/to/file.txt")