Update reference docs to use PropertySourcesPlaceholderConfigurer

See gh-28572

Author: gorisanson

src/docs/asciidoc/web/webflux.adoc

@@ -1540,7 +1540,7 @@ extracts the name, version, and file extension:
 ----
 
 URI path patterns can also have embedded `${...}` placeholders that are resolved on startup
-through `PropertyPlaceHolderConfigurer` against local, system, environment, and other property
+through `PropertySourcesPlaceholderConfigurer` against local, system, environment, and other property
 sources. You ca use this to, for example, parameterize a base URL based on some external
 configuration.
 

src/docs/asciidoc/web/webmvc.adoc

@@ -1712,7 +1712,7 @@ extracts the name, version, and file extension:
 ----
 
 URI path patterns can also have embedded `${...}` placeholders that are resolved on startup
-by using `PropertyPlaceHolderConfigurer` against local, system, environment, and other property
+by using `PropertySourcesPlaceholderConfigurer` against local, system, environment, and other property
 sources. You can use this, for example, to parameterize a base URL based on some external
 configuration.