Describe the bug
The combination of #each and the animate directive doesn't allow comments.

To Reproduce
See https://svelte.dev/repl/aa902b5c51fd4e79be8dda8267fe7485?version=3.15.0.
There will be an error message at the bottom.
If the comment is deleted, the error goes away.

Expected behavior
Comments should be ignored and not cause an error.

Severity
This prevents documenting some code.