chore(ci): remove ng12-15 apps, add ng16-17 for stencil nightlies (#28945)

Issue number: Internal

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## What is the current behavior?
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The Stencil nightlies are still attempting to run old Angular test apps
and does not test ng16/17

## What is the new behavior?
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- Removed ng12-15 test apps
- Added ng16-17 test apps

I opted to remove ng14-15 because we are in the process of dropping
support for it in Ionic 8.

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

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## Other information

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