Upgrade lit-labs/signals from ^0.1.2 → ^0.2.0 for webcomponents

[amal-k-joy]

We need to upgrade the lit-labs/signals to latest. Current renovate PR has some build failing

Acceptance criteria

• Checkout to a new feature branch and upgrade lit-labs/signals from ^0.1.2 → ^0.2.0
• Run and fix CI checks including build and test
• Perform a regression on components that uses signals.
• Open a new PR
• Close the renovate PR

[ruchas31]

I had upgraded lit-labs/signals from 0.1.2 to 0.2.0 but while building the application, the error observed is:
TS4020: 'extends' clause of exported class 'CDSCoachmarkBody' has or is using private name 'SignalWatcherApi'
There error exists everywhere lit-labs/signals has been imported (e.g. Coachmark, Interstitial Screen & Step Flow Pattern Components).

The new version 0.2.0 has a TypeScript issue where the SignalWatcherApi interface is private, causing compilation errors when used directly in class extends clauses. This looks to be a known reproducible issue in the Lit-Labs/Signals library - see issue lit/lit#5192. There is an open PR attached to that Lit issue.

As discussed in standup, I am removing this issue from the sprint and adding blocked label. We can wait for the Lit Library to fix that issue in a new version. I will also close the Renovate bot PR - #8906.

FYI @amal-k-joy