Hide utility class constructors

Update all utility classes so that they have a private constructor. This
prevents users from accidentally creating an instance, when they should
just use the static methods directly.

Issue gh-8945

taglibs/src/main/java/org/springframework/security/taglibs/TagLibConfig.java

@@ -51,6 +51,9 @@ public final class TagLibConfig {
 		}
 	}
 
+	private TagLibConfig() {
+	}
+
 	/**
 	 * Returns EVAL_BODY_INCLUDE if the authorized flag is true or UI security has been
 	 * disabled. Otherwise returns SKIP_BODY.