chore(ci): use node v20 for github actions (#30088)

Issue number: N/A

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## What is the current behavior?
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Github actions are failing due to using node v18.

[Failing
example](https://github.com/ionic-team/ionic-framework/actions/runs/12379078209/job/34552448830)

## What is the new behavior?
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this PR. -->

- Github actions have been updated to use node v20.

[Passing
example](https://github.com/ionic-team/ionic-framework/actions/runs/12379780879/job/34554955539)

## Does this introduce a breaking change?

- [ ] Yes
- [x] No

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## Other information

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screenshots of how the component looks before and after the change. -->

N/A