fix: check for scrollEl existence

[stewones]

ion-content is breaking CI environments when the scrollable element is not reachable and the consumer needs to run content.scrollToBottom()

---

What is the current behavior?

N/A

What is the new behavior?

N/A

Does this introduce a breaking change?

• Yes
• No

Other information

TypeError: Cannot read properties of undefined (reading 'scrollHeight')

      at Content.<anonymous> (../../node_modules/@ionic/core/components/ion-content.js:242:28)
      at fulfilled (../../node_modules/tslib/tslib.js:166:62)
      at _ZoneDelegate.Object.<anonymous>._ZoneDelegate.invoke (../../node_modules/zone.js/bundles/zone.umd.js:411:30)
      at AsyncTestZoneSpec.Object.<anonymous>.AsyncTestZoneSpec.onInvoke (../../node_modules/zone.js/bundles/zone-testing.umd.js:1261:47)
      at ProxyZoneSpec.Object.<anonymous>.ProxyZoneSpec.onInvoke (../../node_modules/zone.js/bundles/zone-testing.umd.js:297:43)

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Name	Status	Preview	Comments	Updated (UTC)
ionic-framework	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Apr 27, 2024 9:19pm

[sean-perkins]

Hello @stewones, can you create an issue with a minimal reproduction for me to test against?

The scroll element is set during render. I need more context to understand what issue is being experienced and why this change is the best way to resolve it.

e.g. If this issue impacts scrollToBottom, what about scrollToPoint and scrollToTop?

Thanks!

[stewones]

hey @sean-perkins
just did it #29419

[stewones]

regarding scrollToPoint and scrollToTop, they're prob broken as well. I'm happy to patch them as well if you think this should be baked into the core.