`Unrecognized configuration key` warnings since 2.8.0.Final if using config property with list values in YAML
### Describe the bug

```yaml
quarkus:
  arc:
    ignored-split-packages:
      - foo.bar
```
results in a build warning in 2.8.0.Final, but not in 2.7.5.Final:
```
[INFO] --- quarkus-maven-plugin:2.8.0.Final:build (default) @ code-with-quarkus ---
[WARNING] [io.quarkus.config] Unrecognized configuration key "quarkus.arc.ignored-split-packages[0]" was provided; it will be ignored; verify that the dependency extension for this configuration is set or that you did not make a typo
[INFO] [io.quarkus.deployment.QuarkusAugmentor] Quarkus augmentation completed in 1443ms
```

### Expected behavior

No warning, the key is valid.

### Actual behavior

`Unrecognized configuration key` warning

### How to Reproduce?

[q_build-warnings.zip](https://github.com/quarkusio/quarkus/files/8466095/q_build-warnings.zip)

`mvn clean package -DskipTests`

### Output of `uname -a` or `ver`

_No response_

### Output of `java -version`

17.0.2, vendor: BellSoft

### GraalVM version (if different from Java)

_No response_

### Quarkus version or git rev

2.8.0.Final

### Build tool (ie. output of `mvnw --version` or `gradlew --version`)

Apache Maven 3.8.4

### Additional information

Also happens with e.g. `quarkus.qute.suffixes`.

Does not happen when using `application.properties`.
diff --git a/core/deployment/src/main/java/io/quarkus/deployment/steps/ConfigGenerationBuildStep.java b/core/deployment/src/main/java/io/quarkus/deployment/steps/ConfigGenerationBuildStep.java
index 167849ed1c3..be3f6406bce 100644
--- a/core/deployment/src/main/java/io/quarkus/deployment/steps/ConfigGenerationBuildStep.java
+++ b/core/deployment/src/main/java/io/quarkus/deployment/steps/ConfigGenerationBuildStep.java
@@ -200,9 +200,7 @@ private static void reportUnknownBuildProperties(LaunchMode launchMode, Set<Stri
         // So it only reports during the build, because it is very likely that the property is available in runtime
         // and, it will be caught by the RuntimeConfig and log double warnings
         if (!launchMode.isDevOrTest()) {
-            for (String unknownProperty : unknownBuildProperties) {
-                ConfigDiagnostic.unknown(unknownProperty);
-            }
+            ConfigDiagnostic.unknownProperties(new ArrayList<>(unknownBuildProperties));
         }
     }
 
['core/deployment/src/main/java/io/quarkus/deployment/steps/ConfigGenerationBuildStep.java']