fix: handle path with dollar signs

[merceyz]

What's the problem this PR addresses?

If the filepath contains two dollar signs ($$) then the replacement here

svelte-loader/index.js

Line 49 in 00e8607

return code.replace(/(export default ([^;]*));/, replacement);

removes one of them causing webpack to look for a path that doesn't exist

.yarn/$$virtual/svelte-loader-virtual-ffb4749d44/2/svelte-loader/lib/hot-api.js turns into .yarn/$virtual/svelte-loader-virtual-ffb4749d44/2/svelte-loader/lib/hot-api.js

How did you fix it?

Use the callback version of replace which uses the literal value provided