Bump xalan:xalan from 2.7.2 to 2.7.3 in /freemarker-docgen-core

Bumps xalan:xalan from 2.7.2 to 2.7.3.

---
updated-dependencies:
- dependency-name: xalan:xalan
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
diff --git a/freemarker-docgen-core/pom.xml b/freemarker-docgen-core/pom.xml
index e804d85..a53090d 100644
--- a/freemarker-docgen-core/pom.xml
+++ b/freemarker-docgen-core/pom.xml
@@ -95,7 +95,7 @@
             <!-- Needed on Java 9+ -->
             <groupId>xalan</groupId>
             <artifactId>xalan</artifactId>
-            <version>2.7.2</version>
+            <version>2.7.3</version>
             <exclusions>
                 <exclusion>
                     <groupId>xml-apis</groupId>