Harmonize visibility of RuntimeHints builders

Closes gh-28835

spring-core/src/main/java/org/springframework/aot/hint/ResourceBundleHint.java

@@ -33,7 +33,7 @@ public final class ResourceBundleHint implements ConditionalHint {
 	private final String baseName;
 
 	@Nullable
-	private TypeReference reachableType;
+	private final TypeReference reachableType;
 
 
 	ResourceBundleHint(Builder builder) {
@@ -83,6 +83,10 @@ public final class ResourceBundleHint implements ConditionalHint {
 		@Nullable
 		private TypeReference reachableType;
 
+		Builder(String baseName) {
+			this.baseName = baseName;
+		}
+
 		/**
 		 * Make this hint conditional on the fact that the specified type
 		 * can be resolved.

spring-core/src/main/java/org/springframework/aot/hint/ResourceHints.java

@@ -137,7 +137,7 @@ public class ResourceHints {
 	 * @return {@code this}, to facilitate method chaining
 	 */
 	public ResourceHints registerResourceBundle(String baseName, @Nullable Consumer<ResourceBundleHint.Builder> resourceHint) {
-		ResourceBundleHint.Builder builder = new ResourceBundleHint.Builder().baseName(baseName);
+		ResourceBundleHint.Builder builder = new ResourceBundleHint.Builder(baseName);
 		if (resourceHint != null) {
 			resourceHint.accept(builder);
 		}

spring-core/src/main/java/org/springframework/aot/hint/ResourcePatternHints.java

@@ -71,6 +71,9 @@ public final class ResourcePatternHints {
 
 		private final Set<ResourcePatternHint> excludes = new LinkedHashSet<>();
 
+		Builder() {
+		}
+
 		/**
 		 * Includes the resources matching the specified pattern.
 		 * @param reachableType the type that should be reachable for this hint to apply