Polish "Deprecate support for theme" changes

See gh-29202

spring-web/src/main/java/org/springframework/web/context/support/AbstractRefreshableWebApplicationContext.java

@@ -57,7 +57,7 @@ import org.springframework.web.context.ServletContextAware;
  * {@link org.springframework.context.support.AbstractApplicationContext},
  * this class detects a bean of type {@link org.springframework.ui.context.ThemeSource}
  * in the context, under the special bean name "themeSource".
- * Theme support is deprecated as of 6.0
+ * Theme support is deprecated as of 6.0 with no direct replacement.
  *
  * <p><b>This is the web context to be subclassed for a different bean definition format.</b>
  * Such a context implementation can be specified as "contextClass" context-param

spring-web/src/main/java/org/springframework/web/context/support/GenericWebApplicationContext.java

@@ -52,7 +52,7 @@ import org.springframework.web.context.ServletContextAware;
  * <p>In addition to the special beans detected by
  * {@link org.springframework.context.support.AbstractApplicationContext AbstractApplicationContext},
  * this class detects a {@link ThemeSource} bean in the context, with the name "themeSource".
- * Theme support is deprecated as of 6.0
+ * Theme support is deprecated as of 6.0 with no direct replacement.
  *
  * <p>If you wish to register annotated <em>component classes</em> with a
  * {@code GenericWebApplicationContext}, you can use an

spring-web/src/main/java/org/springframework/web/context/support/StaticWebApplicationContext.java

@@ -50,7 +50,7 @@ import org.springframework.web.context.ServletContextAware;
  * {@link org.springframework.context.support.AbstractApplicationContext},
  * this class detects a bean of type {@link org.springframework.ui.context.ThemeSource}
  * in the context, under the special bean name "themeSource".
- * Theme support is deprecated as of 6.0
+ * Theme support is deprecated as of 6.0 with no direct replacement.
  *
  * @author Rod Johnson
  * @author Juergen Hoeller