Remove Objenesis

[tobiasKaminsky]

Objenesis update fails, but we might not even need it.
(A local test run with a few Mockito unit tests worked, thus running now full CI)

🖼️ Screenshots

🏚️ Before	🏡 After
B	A

🏁 Checklist

• ⛑️ Tests (unit and/or integration) are included or not needed
• 🔙 Backport requests are created or not needed: /backport to stable-xx.x
• 📅 Milestone is set
• 🌸 PR title is meaningful (if it should be in the changelog: is it meaningful to users?)

🤖 AI (if applicable)

• The content of this PR was partly or fully generated using AI

[github-actions]

APK file: https://github.com/nextcloud/android/actions/runs/32011219974/artifacts/9282307354
To test this change/fix you can simply download above APK file and install and test it in parallel to your existing Nextcloud app.
(please click on link to get QR code displayed)

[github-actions]

APK file: https://github.com/nextcloud/android/actions/runs/32100841358/artifacts/9311609412
To test this change/fix you can simply download above APK file and install and test it in parallel to your existing Nextcloud app.
(please click on link to get QR code displayed)

[github-actions]

APK file: https://github.com/nextcloud/android/actions/runs/32103618553/artifacts/9312539172
To test this change/fix you can simply download above APK file and install and test it in parallel to your existing Nextcloud app.
(please click on link to get QR code displayed)

[github-actions]

APK file: https://github.com/nextcloud/android/actions/runs/32106625178/artifacts/9313552066
To test this change/fix you can simply download above APK file and install and test it in parallel to your existing Nextcloud app.
(please click on link to get QR code displayed)

[github-actions]

blue-Light-Screenshot test failed, but no output was generated. Maybe a preliminary stage failed.

[github-actions]

Codacy

SpotBugs

Category	Base	New
Bad practice	32	32
Correctness	59	59
Dodgy code	207	207
Experimental	1	1
Malicious code vulnerability	2	2
Multithreaded correctness	25	25
Performance	39	39
Security	19	19
Total	384	384

[github-actions]

APK file: https://github.com/nextcloud/android/actions/runs/32109714716/artifacts/9314778817
To test this change/fix you can simply download above APK file and install and test it in parallel to your existing Nextcloud app.
(please click on link to get QR code displayed)