Update spring boot to v4 (major)

[renovate[bot]]

This PR contains the following updates:

Package	Change	Age	Confidence
org.springframework.boot:spring-boot-dependencies (source)	3.5.8 -> 4.0.0
org.springframework.boot:spring-boot-starter-parent (source)	3.5.8 -> 4.0.0

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[!WARNING] Some dependencies could not be looked up. Check the Dependency Dashboard for more information.

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Release Notes

spring-projects/spring-boot (org.springframework.boot:spring-boot-dependencies)

v4.0.0

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Configuration

📅 Schedule: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about these updates again.

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• [ ] If you want to rebase/retry this PR, check this box

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