TypeScript compiler error that breaks transitions in tutorials.

[AndrewJakubowicz]

Found while manually testing out the whole site #1127. Then confirmed the issue is in production.

Impact of issue is that while navigating the Learn tutorials a certain section may break and stop working until the user refreshes the page.
I have not root caused the issue, and why it appears on only certain tutorials and certain direction navigations.

Repros

• Build a tooltip element: Progressing from Step 8 -> Step 9.
• Build a word viewer!: Progressing from Step 2 -> Step 1.

Every other tutorial does not have this issue. (Manually checked both forward and backwards navigation).

Investigation

The error message matches microsoft/TypeScript#49738. A possible solution may be updating TypeScript.

I am not able to reproduce this issue on local dev, only preview environments and production.
A repro is possible on Firefox.

[AndrewJakubowicz]

Issue seems to be the addition of a new import to lit/directives in both cases.

[AndrewJakubowicz]

Maybe related to microsoft/TypeScript#52636?

[AndrewJakubowicz]

I've manually verified that both google/playground-elements#369 and upgrading playground-elements to TS version 5.0.4 fixes the issue.

Is there a preference for which should be tackled?

We'll probably want to update the bundled TypeScript within playground-elements to TS 5 eventually.