fix: upgrade com.formdev:flatlaf from 3.5.4 to 3.6

Snyk has created this PR to upgrade com.formdev:flatlaf from 3.5.4 to 3.6.

See this package in maven:
com.formdev:flatlaf

See this project in Snyk:
https://app.snyk.io/org/itext-ci/project/758d7110-d710-4e37-9501-956f6ea18c2b?utm_source=github&utm_medium=referral&page=upgrade-pr

Author: snyk-bot

pom.xml

@@ -76,7 +76,7 @@
 
     <!-- Application dependencies -->
     <dom4j.version>2.1.4</dom4j.version>
-    <flatlaf.version>3.5.4</flatlaf.version>
+    <flatlaf.version>3.6</flatlaf.version>
     <icu4j.version>76.1</icu4j.version>
     <itext.version>9.1.0</itext.version>
     <jackson.version>2.18.3</jackson.version>