Downgrade to Java 11.

Downgrades to Java 11 in order to support consumers that are not on
Java 16 yet.

Change-Id: Ia5930d1c40d0090ca145fd14c0b63a139e4ac970
diff --git a/runtime/src/main/java/eu/mulk/quarkus/googlecloud/jsonlogging/Label.java b/runtime/src/main/java/eu/mulk/quarkus/googlecloud/jsonlogging/Label.java
index 02f7034..7c5d14d 100644
--- a/runtime/src/main/java/eu/mulk/quarkus/googlecloud/jsonlogging/Label.java
+++ b/runtime/src/main/java/eu/mulk/quarkus/googlecloud/jsonlogging/Label.java
@@ -1,8 +1,44 @@
 package eu.mulk.quarkus.googlecloud.jsonlogging;
 
-public record Label(String key, String value) {
+import java.util.Objects;
+
+public final class Label {
+
+  private final String key;
+  private final String value;
+
+  private Label(String key, String value) {
+    this.key = key;
+    this.value = value;
+  }
 
   public static Label of(String key, String value) {
     return new Label(key, value);
   }
+
+  public String key() {
+    return key;
+  }
+
+  public String value() {
+    return value;
+  }
+
+  @Override
+  public boolean equals(Object obj) {
+    if (obj == this) return true;
+    if (obj == null || obj.getClass() != this.getClass()) return false;
+    var that = (Label) obj;
+    return Objects.equals(this.key, that.key) && Objects.equals(this.value, that.value);
+  }
+
+  @Override
+  public int hashCode() {
+    return Objects.hash(key, value);
+  }
+
+  @Override
+  public String toString() {
+    return "Label[" + "key=" + key + ", " + "value=" + value + ']';
+  }
 }