invalid-animation error when a keyed each block contains a comment in addition to the sole child

[maxlath]

Describe the bug
When the each block contains a comment, the compiler throws an invalid-animation error

The reason seems to be that EachBlock doesn't filter-out comments when testing if this.children.length !== 1

To Reproduce
See https://svelte.dev/repl/d868b86121f64a67986c420d21e32bc8?version=3.32.3

Expected behavior
Comments should be ignored by the validation

Severity
Somewhat annoying, as realizing that the comment counts as a child might take a while.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[maxlath]

this is still the case in v3.38.3

[dummdidumm]

Duplicate of #3999