ci(build): bump deprecated actions to match release job versions

[IronCrest-sudo]

What

Bumps the deprecated actions in the build job to match the versions already used in the release job:

Action	Before	After
actions/checkout	v4	v7
actions/setup-java	v4	v5
actions/upload-artifact	v4	v5
gradle/actions/wrapper-validation	v4	v5
gradle/actions/setup-gradle	v4	v5

Why

The build job's run showed two warnings:

• setup-java v4 is deprecated and will no longer receive updates
• Several v4 actions target Node.js 20 but are being forced to run on Node.js 24

The release job in this same workflow was already on the newer versions, so the build job had drifted behind it.

How this was done

Bumped one action at a time across four separate commits, so any single bump can be bisected/reverted independently if it breaks the build:

1. actions/checkout v4 -> v7
2. actions/setup-java v4 -> v5
3. actions/upload-artifact v4 -> v5
4. gradle/actions/wrapper-validation + gradle/actions/setup-gradle v4 -> v5

Test status

CI on this PR is the real test (build + packZips on the actual project) — check the Actions tab on this PR for the run result before merging.