Fix hierarchy generation crashing due to missing null check

[bjosttveit]

Description

The Javascript type system is amazing as always, this error was due to the fact that typeof null === 'object' returns true, combined with the fact that any in Typescript does not do type-narrowing very well. Switching any to unknown made the mistake more apparent, now warning that obj could be either object | null which gave a type error in Object.keys.

A lesson here is that unknown can be more useful in cases like this instead of using any explicitly when you dont know the type.

Related Issue(s)

• https://altinn.slack.com/archives/C02EJ9HKQA3/p1713947469018009

Verification/QA

• Manual functionality testing
  • [x] I have tested these changes manually
  • [ ] Creator of the original issue (or service owner) has been contacted for manual testing (or will be contacted when released in alpha)
  • [ ] No testing done/necessary
• Automated tests
  • [ ] Unit test(s) have been added/updated
  • [ ] Cypress E2E test(s) have been added/updated
  • [x] No automatic tests are needed here (no functional changes/additions)
  • [ ] I want someone to help me make some tests
• UU/WCAG (follow these guidelines until we have our own)
  • [ ] I have tested with a screen reader/keyboard navigation/automated wcag validator
  • [x] No testing done/necessary (no DOM/visual changes)
  • [ ] I want someone to help me perform accessibility testing
• User documentation @ altinn-studio-docs
  • [ ] Has been added/updated
  • [x] No functionality has been changed/added, so no documentation is needed
  • [ ] I will do that later/have created an issue
• Support in Altinn Studio
  • [ ] Issue(s) created for support in Studio
  • [x] This change/feature does not require any changes to Altinn Studio
• Sprint board
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  • [ ] I don't have permissions to do that, please help me out
• Labels
  • [x] I have added a kind/* label to this PR for proper release notes grouping
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[sonarcloud[bot]]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud