deps: update dependency org.springframework.boot:spring-boot-starter-…

…test to v2.6.6 (#756)

* deps: update dependency org.springframework.boot:spring-boot-starter-test to v2.6.6

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samples/snippets/cloud-client/src/pom.xml

@@ -105,7 +105,7 @@
     <dependency>
       <groupId>org.springframework.boot</groupId>
       <artifactId>spring-boot-starter-test</artifactId>
-      <version>2.6.5</version>
+      <version>2.6.6</version>
       <scope>test</scope>
     </dependency>
     <dependency>