Warn when using deprecated configurations

[radcortez]

We used to warn when using deprecated configuration. This was only for the old @ConfigRoot, so when we moved to @ConfigMapping, we lost the warnings.

This PR adds the warnings for @Deprecated properties in @ConfigMapping and remove the old code for @ConfigRoot. We may miss warnings for @ConfigRoot, but we already have a warning for users to migrate to @ConfigMapping, which would reenable the feature.

[quarkus-bot]

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[github-actions]

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[quarkus-bot]

Status for workflow Quarkus CI

This is the status report for running Quarkus CI on commit 9faa60a.

✅ The latest workflow run for the pull request has completed successfully.

It should be safe to merge provided you have a look at the other checks in the summary.

You can consult the Develocity build scans.

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Flaky tests - Develocity

⚙️ Maven Tests - JDK 17

📦 integration-tests/devmode

✖ io.quarkus.test.devui.DevUIGrpcSmokeTest.testTestService - History

• Too many recursions, message not returned for id [134981005] - java.lang.RuntimeException

java.lang.RuntimeException: Too many recursions, message not returned for id [134981005]
	at io.quarkus.devui.tests.DevUIJsonRPCTest.objectResultFromJsonRPC(DevUIJsonRPCTest.java:168)
	at io.quarkus.devui.tests.DevUIJsonRPCTest.objectResultFromJsonRPC(DevUIJsonRPCTest.java:171)
	at io.quarkus.devui.tests.DevUIJsonRPCTest.objectResultFromJsonRPC(DevUIJsonRPCTest.java:171)
	at io.quarkus.devui.tests.DevUIJsonRPCTest.objectResultFromJsonRPC(DevUIJsonRPCTest.java:171)
	at io.quarkus.devui.tests.DevUIJsonRPCTest.objectResultFromJsonRPC(DevUIJsonRPCTest.java:171)
	at io.quarkus.devui.tests.DevUIJsonRPCTest.objectResultFromJsonRPC(DevUIJsonRPCTest.java:171)
	at io.quarkus.devui.tests.DevUIJsonRPCTest.objectResultFromJsonRPC(DevUIJsonRPCTest.java:171)

[gsmet]

I wonder if we should also have a way to report relocated properties as deprecated?

Because we sometimes use this infra to handle deprecations and maybe we need a way to declare that a given relocation class is handling deprecated properties?

And my understanding is that we could get both the deprecated property and the new one in this case?

Note that not all relocations are related to deprecations.

[radcortez]

Yes, let's improve this. This was just to add the missing functionality to mappings. Now with the doc work, we can iterate and improve this.