fix: samples/server/petstore/springboot-virtualan/pom.xml to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JAVA-ORGAPACHETOMCATEMBED-10674391
- https://snyk.io/vuln/SNYK-JAVA-COMFASTERXMLJACKSONCORE-10500754

Author: snyk-bot

samples/server/petstore/springboot-virtualan/pom.xml

@@ -10,7 +10,7 @@
         <maven.compiler.source>${java.version}</maven.compiler.source>
         <maven.compiler.target>${java.version}</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <springdoc.version>1.6.14</springdoc.version>
+        <springdoc.version>1.7.0</springdoc.version>
         <virtualan.version>2.5.2</virtualan.version>
         <swagger-ui.version>5.3.1</swagger-ui.version>
     </properties>