chore: set minimal server version to 1.31

Author: bevzzz

src/main/java/io/weaviate/client6/v1/internal/VersionSupport.java

@@ -3,7 +3,7 @@
 import java.util.Arrays;
 
 public final class VersionSupport {
-  public static final SemanticVersion MINIMAL_SUPPORTED_VERSION = new SemanticVersion(1, 33);
+  public static final SemanticVersion MINIMAL_SUPPORTED_VERSION = new SemanticVersion(1, 31);
 
   /**
    * Returns true if the {@code version} is the same as or older than the