fix: pom.xml to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JAVA-CAUHNHAPIFHIR-8344146
- https://snyk.io/vuln/SNYK-JAVA-CAUHNHAPIFHIR-8344149
- https://snyk.io/vuln/SNYK-JAVA-CAUHNHAPIFHIR-8366323
- https://snyk.io/vuln/SNYK-JAVA-CAUHNHAPIFHIR-8366327
- https://snyk.io/vuln/SNYK-JAVA-COMMONSIO-8161190

pom.xml

@@ -81,7 +81,7 @@
     <dependency>
       <groupId>ca.uhn.hapi.fhir</groupId>
       <artifactId>hapi-fhir-structures-r4</artifactId>
-      <version>7.4.4</version>
+      <version>7.6.0</version>
     </dependency>
 
     <dependency>