Update io.spring.javaformat to 0.0.28

Closes gh-9710

gradle.properties

@@ -1,5 +1,5 @@
 aspectjVersion=1.9.6
-springJavaformatVersion=0.0.27
+springJavaformatVersion=0.0.28
 springBootVersion=2.4.2
 openSamlVersion=3.4.6
 version=5.5.0-SNAPSHOT